HP OpenVMS Systems Documentation

The following figures show the qualifiers that can be used in BACKUP save, restore, copy, compare and list operations. The figures also indicate valid combinations of BACKUP qualifiers.

• Figure G-1 shows command qualifiers used in save operations.
• Figure G-2 shows input file-selection qualifiers used in save operations.
• Figure G-3 shows output save-set qualifiers used in save operations.
• Figure G-4 shows command qualifiers used in restore operations.
• Figure G-5 shows input save-set qualifiers used in restore operations.
• Figure G-6 shows output file qualifiers used in restore operations.
• Figure G-7 shows command qualifiers used in copy operations.
• Figure G-8 shows input file-selection qualifiers used in copy operations.
• Figure G-9 shows output file qualifiers used in copy operations.
• Figure G-10 shows command qualifiers used in compare operations.
• Figure G-11 shows input file-selection qualifiers used in compare operations.
• Figure G-12 shows input save-set qualifiers used in compare operations.

Figure G-1 Command Qualifiers Used in Save Operations

Figure G-2 Input File-Selection Qualifiers Used in Save Operations

Figure G-3 Output Save-Set Qualifiers Used in Save Operations

Figure G-4 Command Qualifiers Used in Restore Operations

Figure G-5 Input Save-Set Qualifiers Used in Restore Operations

Figure G-6 Output File Qualifiers Used in Restore Operations

Figure G-7 Command Qualifiers Used in Copy Operations

Figure G-8 Input File-Selection Qualifiers Used in Copy Operations

Figure G-9 Output File Qualifiers Used in Copy Operations

Figure G-10 Command Qualifiers Used in Compare Operations

Figure G-11 Input File-Selection Qualifiers Used in Compare Operations

Figure G-12 Input Save-Set Qualifiers Used in Compare Operations

The following sections describe the MONITOR record formats.

Binary performance data is written into the MONITOR recording file when a MONITOR request indicates recording. A record is written to this file once per interval for each requested class. The record contains a predefined set of data for each of the requested performance classes.

The recording file is created when a MONITOR request is initiated, and is closed when the request terminates. The MONITOR recording file may be used as a source file to format and display the data on a terminal, to create a summary file, or to record a new recording file with different characteristics.

The MONITOR recording file is an OpenVMS RMS sequential file with variable-length records. Each record in the file begins with a one-byte type field. The remaining fields are different in length and format for each record type. The following list contains three categories of record types:

• Customer control record
• HP control record
• Class record

Customer control records may appear anywhere in the recording file. They are not generated by MONITOR and are ignored by MONITOR when it reads the file.

The first records in the MONITOR recording file, excluding customer control records, are HP control records. The beginning of the file has three types of HP control records: the file header record, the system information record, and the record RMS file name record. Node transition records are also control records, but can appear anywhere in the file.

Class records, which contain data on requested performance classes, follow the HP control records. The class record is generally written once per interval for each class being recorded. An exception to this rule occurs when several class records are required to contain data for a single class over a single interval. This can occur for the PROCESSES class when too many processes exist to be accommodated by the maximum record size.

Unique numbers are assigned to each MONITOR record type. Record type numbers 0--127 are reserved for class records; numbers 128--191 are reserved for HP control records; numbers 192--255 are reserved for customer control records.

MONITOR generates 29 record types. The following table lists the MONITOR record types and their numbers, with associated class types. (For an explanation of MONITOR class types, refer to Section H.4.1.)

The following sections define the contents of each field within each record type. Record type and record size are given in decimal representation. References to system time indicate time values in system time format (64-bit format).

The field offset names listed are not defined within MONITOR. However, HP recommends that you define and use these offset names when you work with MONITOR output records.

The following example is the suggested naming convention for the field offset names:

CCC is a record type or class mnemonic.

X is a one-letter code indicating the size of the data item, as follows:

B for byte
W for word
L for longword
Q for quadword
O for octaword
T for ASCII string

DDDDD is the name describing the data item.

In the following tables that describe the record fields, the size of the data is shown in parentheses following the description of the field contents.

H.3 HP Control Records

The four types of HP control records are:

• File header record
• System information record
• Node transition record
• RMS file record

Each file has one header record, which contains information applicable to all classes of performance data contained in the file. It must be the first record (except for customer control records) in the file.

One system information record exists per node per file. The record contains information about the system being monitored and follows the header record in the file.

H.3.1 File Header Record

The file header record has a record type of 128 and a size of 259 bytes. Figure H-1 illustrates the format of the file header record.

Figure H-1 File Header Record Format

The following table describes the fields in the file header record:

H.3.2 System Information Record

Figure H-2 System Information Record Format

The following table describes the fields in the system information record:

The node transition record has a record type of 130 and a size of 2 bytes. Figure H-3 illustrates the format of the node transition record.

Figure H-3 Node Transition Record Format

The following table describes the fields in the node transition record:

The RMS file record has a record type of 131 and a variable size that depends on the number of RMS files and length of the file name string. Figure H-4 illustrates the format of the RMS file record.

Figure H-4 RMS File Record Format

The following table describes the fields in the RMS file record:

The MONITOR recording file contains one class record for each requested class for every collection interval, except for the PROCESSES class. (See Section H.4.2.12 for more information about the PROCESSES class records.) For example, if a MONITOR user requested to record five classes (excluding PROCESSES) for a duration of 100 collection intervals, the file would contain 500 class records. Class records occur in order of increasing type number within an interval. The first class record for a given interval follows the last class record for the previous interval.

H.4.1 Class Type Formats

The two basic class types are system classes and component classes. A class record for a system class generally consists of counts for systemwide activities (such as page faults), whereas a class record for a component class normally contains a count for each element of a measured activity (such as I/O operations for each disk in the system).

Specifically, a class record for a system class consists of a class header followed by a data block. A class record for a component class has a class header followed by a class prefix and one data block per element.

Figure H-5 illustrates the format for class records.

Figure H-5 Class Record Format

The class header is the first part of every class record. Its format is independent of class. The class header is 13 bytes long.

Figure H-6 illustrates the format of the class header.

Figure H-6 Class Header Format

The following table describes the fields in the class header:

The class prefix always follows the class header for component class records. It contains data describing the number of elements (for example, processes for the PROCESSES class, disks for the DISK class) represented by the class records for the current collection interval. Unlike system class records, which have one data block per record, component classes have one data block per element.

One of the class prefix data items describes the number of elements (and therefore the number of data blocks) included in the class record. The other class prefix data item is used only for the PROCESSES class, and describes the number of processes included in the interval. The following discussion applies only to the PROCESSES class.

It is possible to monitor a number of processes so large that the required number of data blocks for one collection interval does not fit into a single maximum size record. In this case, the required number of PROCESSES class records is created to fully describe the processes.

All class headers in the set of PROCESSES class records for a given interval are identical, except for the setting of bit 0 in the MNR_CLS$W_FLAGS field. This bit is set to 1 for all records except the last, for which it is set to 0.

The class prefixes in the set of class records vary, as described in the table following the next figure. The contents of the MNR_CMP$L_ELTCT field depends on the number of data blocks contained in the record; the contents of the MNR_CMP$L_PCTINT field remain constant for each record in the set. All records in the set except the last contain as many data blocks as will fit into the maximum size record (32000 bytes). The last record in the set contains the remaining data blocks.

Figure H-7 illustrates the class prefix format.

Figure H-7 Class Prefix Format

The following table describes the fields in the class prefix. The class prefix is 8 bytes long.

The size and format of each data block and the number of blocks per record depend on the class. System classes have one data block per record. Component classes have one data block per element. The fields within each block are performance data items.

The following sections describe the data items within the data block for each class. Every data item falls into one of three categories. It is either a count, a level, or an informational item. A count is a numeric quantity that increases at each succeeding interval for the duration of a system boot. A level is a numeric quantity that may increase or decrease at each succeeding interval. An informational item represents data that, rather than being a unit of performance measurement (as are the first two types), is descriptive in nature.

In the tables that follow, item types are identified by the letters C (count), L (level), and I (informational). Item types are shown in parentheses, following the length of the field. Class records are listed alphabetically.

H.4.2.1 CLUSTER Class Record

The CLUSTER class record contains data describing clusterwide CPU, memory, and locking activity. The CLUSTER class record has a record type of 19 and a size of 65 bytes. Note that when the CLUSTER class is recorded, the DISK and MODES classes are also recorded, even if not explicitly requested.

Figure H-8 illustrates the format of the CLUSTER class record.

Figure H-8 CLUSTER Class Record Format

The following table describes the fields in the data block for the CLUSTER class record:

The DECNET class record contains data describing the operation of the DECnet for OpenVMS subsystem. The DECNET class record has a record type of 8 and a size of 33 bytes.

Figure H-9 illustrates the format of the DECNET class record.

Figure H-9 DECNET Class Record Format

The following table describes the fields in the data block for the DECNET class record:

The DISK class record contains data describing all disk devices in the system. The DISK class record has a record type of 12; its size depends on the number of disks being monitored. The size, in bytes, is calculated by adding the size of the class header, the class prefix, and the data blocks contained in the record. This is shown in the following formula:

13 + 8 + (37 * the value of MNR_CMP$L_ELTCT)

Figure H-10 illustrates the format of the DISK class record.

Figure H-10 DISK Class Record Format

The following table describes the fields in the data block for the DISK class record:

The DLOCK class record contains data describing the operation of the Distributed Lock Management facility. The DLOCK class record has a record type of 14 and a size of 73 bytes.

Figure H-11 illustrates the format of the DLOCK class record.

Figure H-11 DLOCK Class Record Format

The following table describes the fields in the data block for the DLOCK class record:

The FCP class record contains data describing the operation of the file system ACPs. The FCP class record has a record type of 5 and a size of 61 bytes.

Figure H-12 illustrates the format of the FCP class record.

Figure H-12 FCP Class Record Format

The following table describes the fields in the data block for the FCP class record:

The FILE_SYSTEM_CACHE class record contains data describing the operation of the caches for the file system ACPs and XQPs. The FILE_SYSTEM_CACHE class record has a record type of 11 and a size of 69 bytes.

Figure H-13 illustrates the format of the FILE_SYSTEM_CACHE class record.

Figure H-13 FILE_SYSTEM_CACHE Class Record Format

The following table describes the fields in the data block for the FILE_SYSTEM_CACHE class record:

The I/O class record contains data describing the operation of the I/O subsystem. The I/O class record has a record type of 4 and a size of 69 bytes.

Figure H-14 illustrates the format of the I/O class record.

Figure H-14 I/O Class Record Format

The following table describes the fields in the data block for the I/O class record:

The LOCK class record contains data describing the operation of the lock management subsystem. The LOCK class record has a record type of 7 and a size of 53 bytes.

Figure H-15 illustrates the format of the LOCK class record.

Figure H-15 LOCK Class Record Format

The following table describes the fields in the data block for the LOCK class record:

The MODES class record contains data describing time spent in each of the processor modes. The MODES class record has a record type of 2; its size depends on the number of active CPUs on the system being monitored. The size, in bytes, is calculated by adding the size of the class header, the class prefix, and the data blocks contained in the record. This is shown in the following formula, which assumes that all CPUs are active:

13 + 8 + (33 * MNR_SYI$B_MPCPUS)

Figure H-16 illustrates the format of the MODES class record.

Figure H-16 MODES Class Record Format

The following table describes the fields in the data block for the MODES class record:

The MSCP_SERVER class record contains data describing activities of the MSCP server. The MSCP_SERVER class record has a record type of 21 and a size of 65 bytes.

Figure H-17 illustrates the format of the MSCP_SERVER class record.

Figure H-17 MSCP_SERVER Class Record Format

The following table describes the fields in the data block for the MSCP_SERVER class record:

The PAGE class record contains data describing the operation of the page management subsystem. The PAGE class record has a record type of 3 and a size of 65 bytes.

Figure H-18 illustrates the format of the PAGE class record.

Figure H-18 PAGE Class Record Format

The following table describes the fields in the data block for the PAGE class record:

The PROCESSES class record contains data describing all processes in the system. The PROCESSES class record has a record type of 0; its size depends on the number of processes being monitored. The size, in bytes, is calculated by adding the size of the class header, the class prefix, and the data blocks contained in the record. This is shown in the following formula:

13 + 8 + (67 * the value of MNR_CMP$L_ELTCT)

Figure H-19 illustrates the format of the PROCESSES class record.

Figure H-19 PROCESSES Class Record Format

The following table describes the fields in the data block for the PROCESSES class record:

The RLOCK class record contains data that is useful for monitoring the dynamic lock remastering statistics of a node. The RLOCK class record has a record type of 27 and a size of 41 bytes.

Figure H-20 illustrates the format of the RLOCK class record.

Figure H-20 RLOCK Class Record Format

The following table describes the fields in the data block for the RLOCK class record:

The RMS class record contains data describing Record Management Services for specified files. The RMS class record has a record type of 20. Use the following formula to calculate the record size (the formula calculates the size by adding the size of the class header, the class prefix, and the data blocks contained in the record):

13 + 8 + (273 * MNR_CMP$L_ELTCT)

Figure H-21 illustrates the format of the RMS class record.

Figure H-21 RMS Class Record Format

The following table describes the fields in the data block for the RMS class record:

The SCS class record contains data describing SCS (System Communications Services) activity for all SCS connections in the system, on a per-node basis. The SCS class record has a record type of 15; its size depends on the number of nodes being monitored. The size, in bytes, is calculated by adding the size of the class header, the class prefix, and the data blocks contained in the record. This is shown in the following formula:

13 + 8 + (56 * the value of MNR_CMP$L_ELTCT)

Figure H-22 illustrates the format of the SCS class record.

Figure H-22 SCS Class Record Format

The following table describes the fields in the data block for the SCS class record:

The STATES class record contains data describing the number of processes in each of the scheduler states. The STATES class record has a record type of 1 and a size of 69 bytes.

Figure H-23 illustrates the format of the STATES class record.

Figure H-23 STATES Class Record Format

The following table describes the fields in the data block for the STATES class record:

The SYSTEM class record contains data describing the overall operation of the three major system components (CPU, memory, I/O). The SYSTEM class record has a record type of 17 and a size of 49 bytes. Note that when the SYSTEM class is recorded, the PROCESSES, STATES, and MODES classes are also recorded, even if not explicitly requested.

Figure H-24 illustrates the format of the SYSTEM class record.

Figure H-24 SYSTEM Class Record Format

The following table describes the fields in the data block for the SYSTEM class record:

The TIMER class record contains data that is useful to the OpenVMS executive when monitoring timer queue entries (TQEs). The TIMER class record has a record type of 26 and a size of 29 bytes.

Figure H-25 illustrates the format of the TIMER class record.

Figure H-25 TIMER Class Record Format

The following table describes the contents of each of the TIMER class record fields:

The TRANSACTION class record contains data describing the operations of the DECdtm transaction manager. The TRANSACTION class has a record type of 22 and a size of 69 bytes. Figure H-26 illustrates the format of the TRANSACTION class record.

Figure H-26 TRANSACTION Class Record Format

The following table describes the contents of each of the TRANSACTION class record fields:

H.4.2.20 VBS Class Record (VAX Only)

Figure H-27 illustrates the format of a VBS class record.

Figure H-27 VBS Class Record Format (VAX Only)

The following table describes the fields in the data block for the VBS class record:

H.4.2.21 VECTOR Class Record

13 + 8 + (5 * MNR_SYI$B_VPCPUS)

Figure H-28 illustrates the format of the VECTOR class record.

Figure H-28 VECTOR Class Record Format

The following table describes the contents of each of the VECTOR class record fields:

To support the VECTOR class, MONITOR uses the items MNR_SYI$B_VPCPUS and MNR_SYI$L_VPCONF in the system information record. See the table in Section H.3.2 for details on these items.

SHOW CLUSTER provides a predefined keypad that you can use to enter selected commands. You can add, remove, or reposition windows, scroll their contents, or change the interval at which the display is updated. You can also customize the keypad by redefining the default functions of individual keys.

I.1 Using the Keypad

By default, the numeric keypad is defined as shown in Figure I-1.

Figure I-1 SHOW CLUSTER Default Keypad

Shading over a keypad command indicates that you must press the GOLD key and then the keypad key.

The following table describes each keypad command you can use with the Show Cluster utility. In this table, KPn refers to the keypad key labeled with the number n. For example, KP2 refers to the keypad key labeled with the number 2. All commands shown on the keypad are also discussed in the Command Section of Chapter 20.

Use the DEFINE/KEY command to change the definition of a key. See the DEFINE/KEY command in the Command Section of Chapter 20 for more information.

I.3 Redefining the Arrow Keys

By default, the SHOW CLUSTER arrow keys are set to the EDIT function. This means that you can perform command line editing at the command prompt that is similar to DCL line-mode editing. For example, the left arrow key moves the cursor to the left, or the up arrow key recalls the previous command. See the OpenVMS User's Manual for information about DCL line-mode editing.

The SET FUNCTION keys, shown in the second row of the keypad, redefine the arrow keys to perform a specified function. You can reset the arrow keys from EDIT to PAN, SCROLL, or MOVE with the SET FUNCTION command. For example, if you press the SET FUNCTION SCROLL key, the up, down, right, and left arrow keys are redefined as SCROLL UP 1, SCROLL DOWN 1, SCROLL RIGHT 1, and SCROLL LEFT 1, respectively. (See the Command Section of Chapter 20 for information about specific commands.)

This appendix describes OpenVMS system parameters.

System parameters can be grouped into categories, as shown in Section J.1.1. Also, each parameter can have one or more attributes, listed in Section J.1.1. Each parameter also has a value.

The parameters in this appendix are listed alphabetically along with their attributes.

J.1.1 Parameter Categories and Attributes

The system parameters can be divided into the following categories (see also Table J-1):

The user can also define four parameters: USERD1, USERD2, USER3, and USER4. USERD1 and USERD2 are dynamic.

Attributes for Parameters

Parameters can have one or more of the following attributes:

Table J-1 lists system parameters according to category. Footnotes indicate dynamic and system-specific parameters.

Each parameter has associated default, minimum, and maximum values that define the scope of allowable values. To determine these values, invoke SYSGEN and enter a SHOW [parameter-name] command (with appropriate qualifiers). For example, to display the values for WSMAX, specify SHOW WSMAX; to display the values for the TTY parameters, specify SHOW/TTY. You can also display parameters grouped by attributes. To display DYNAMIC parameters, for example, specify SHOW/DYNAMIC.

Default values for system parameters allow booting on any supported OpenVMS configuration. SYSGEN displays default values under the heading default when you enter the SYSGEN command SHOW [parameter-name] for one of the parameter categories or attributes. Reset the default parameter values with the USE DEFAULT command.

However, to avoid starting all layered products on a system that is not tuned for them, possibly causing the system to become nonoperational, set the STARTUP_P1 system parameter to "MIN."

The computed, installed value referred to in this section is the value derived by the AUTOGEN command procedure. (See the HP OpenVMS System Manager's Manual.)

J.2 Parameter Descriptions

This section describes system parameters and provides guidelines to help you decide whether you should consider modifying the parameters. The following attributes are indicated for the parameters:

AUTOGEN---A
DYNAMIC---D
FEEDBACK---F
GEN---G
MAJOR---M

This section alphabetically lists and describes the system parameters in all categories.

Parameters

ACP_BASEPRIO (D)

ACP_BASEPRIO sets the base priority for all ACPs. The DCL command SET PROCESS/PRIORITY can be used to reset the base priorities of individual ACPs. ACP_BASEPRIO is not applicable for XQPs.

ACP_DATACHECK (D)

ACP_DATACHECK controls the consistency checks that are performed on internal file system metadata such as file headers.

ACP_DATACHECK is a bit mask. The following table shows the bits that are defined currently:

Bit	Description
0	Set this bit to perform consistency checks on read operations. When this bit is set, the IO$M_DATACHECK function modifier is automatically set on all subsequent IO$_READLBLK operations that read file system metadata (see the HP OpenVMS I/O User's Reference Manual).
1	Set this bit to perform consistency checks on write operations. When this bit is set, the IO$M_DATACHECK function modifier is automatically set on all subsequent IO$_WRITELBLK operations that read file system metadata (see the HP OpenVMS I/O User's Reference Manual).
2	Set this bit to perform read-after-write consistency checks. This is similar to setting bit 1, except that in this case the file system does the checks, not the lower level device or disk driver. Note that read-after-write consistency checks are not allowed on deferred writes. Deferred writes are turned off if this bit is set.
3	Reserved for HP use only; must be zero.
4	Reserved for HP use only; must be zero.
5 and 6	These two bits control the checks that are performed on reads and writes of directory blocks. You can select one of four different levels: To Check That... Select This Level... By Setting Bit 6 to... And Bit 5 to... The block is a valid directory block (reads only) 0 0 0 The block is a valid directory block (reads and writes) 1 0 1 The block is a valid directory block and contains valid entries (reads and writes) 2 1 0 The block is a valid directory block and contains valid entries in correct alphanumeric order (reads and writes) 3 1 1 When you set the SYSTEM_CHECK system parameter to 1, you enable level 3 checking of directory blocks. Write errors result in BUGCHECK and crash your system; read errors exit with error status SS$_BADDIRECTORY.
7	Reserved for HP use only; must be zero.

ACP_DINDXCACHE (A,D,F)

ACP_DINDXCACHE controls the size of the directory index cache and the number of buffers used on a cachewide basis. Also, ACP_DINDXCACHE builds a temporary index into the directory file, thereby reducing search time and directory header lookup operations.

ACP_DIRCACHE (A,D,F)

ACP_DIRCACHE sets the number of pages for caching directory blocks. Too small a value causes excessive XQP I/O operations, while too large a value causes excessive physical memory to be consumed by the directory data block cache.

ACP_EXTCACHE (D,F)

ACP_EXTCACHE sets the number of entries in the extent cache. Each entry points to one contiguous area of free space on disk. A specification of 0 means no cache. Too small a value causes excessive XQP I/O operations, while too large a value causes excessive physical memory to be consumed by the extent cache.

ACP_EXTLIMIT (D)

ACP_EXTLIMIT specifies the maximum amount of free space to which the extent cache can point, expressed in thousandths of the currently available free blocks on the disk. For example, if available free space on the disk is 20,000 blocks, a specification of 10 limits the extent cache to 200 blocks.

The computed, installed value is usually adequate. Users with four or more OpenVMS Cluster node systems might want to adjust this parameter.

ACP_FIDCACHE (D,F)

ACP_FIDCACHE sets the number of file identification slots cached. A specification of 1 means no cache. Too small a value causes excessive XQP I/O operations, while too large a value causes excessive physical memory to be consumed by the FID caches.

ACP_HDRCACHE (A,D,F)

ACP_HDRCACHE sets the number of pages for caching file header blocks. Too small a value causes excessive XQP I/O operations, while too large a value causes excessive physical memory to be consumed by the file header caches.

ACP_MAPCACHE (A,D,F)

ACP_MAPCACHE sets the number of pages for caching index file bitmap blocks. Too small a value causes excessive XQP I/O operations, while too large a value causes excessive physical memory to be consumed by the bitmap cache.

ACP_MAXREAD (D)

ACP_MAXREAD sets the maximum number of directory blocks read in one I/O operation.

ACP_MULTIPLE (A,D)

ACP_MULTIPLE enables (1) or disables (0) the default creation of a separate disk XQP cache for each volume mounted on a different device type. Prior to Version 4.0, a separate ACP process was created for each device type if this parameter was enabled. Because ACP operations are now handled by the per process XQP, such separate processes are no longer created. In general, having multiple caches is unnecessary. One large cache is more efficient than several small ones. ACP_MULTIPLE can be overridden on an individual-volume basis with the DCL command MOUNT.

ACP_QUOCACHE (A,D,F)

ACP_QUOCACHE sets the number of quota file entries cached. A specification of 0 means no cache. Too small a value causes excessive XQP I/O operations, while too large a value causes excessive physical memory to be consumed by the quota caches.

ACP_REBLDSYSD

ACP_REBLDSYSD specifies whether the system disk should be rebuilt if it was improperly dismounted with extent caching, file number caching, or disk quota caching enabled. The ACP_REBLDSYSD default value (1) ensures that the system disk is rebuilt. Setting the value to 0 means the disk is not rebuilt.

Depending on the amount of caching enabled on the volume before it was dismounted, the rebuild operation may consume a considerable amount of time. Setting the value of ACP_REBLDSYSD to 0 specifies that the disk should be returned to active service immediately. If you set ACP_REBLDSYSD to 0, you can enter the DCL command SET VOLUME/REBUILD at any time to rebuild the disk.

ACP_SHARE (D)

ACP_SHARE enables (0) or disables (1) the creation of a global section for the first ACP used, enabling succeeding ACPs to share its code. This parameter should be set to 0 when ACP_MULTIPLE is on.

ACP_SWAPFLGS (A,D)

ACP_SWAPFLGS enables or disables swap through the value of a 4-bit number for the following four classes of ACPs:

Bit	Class of ACP
0	Disks mounted by MOUNT/SYSTEM
1	Disks mounted by MOUNT/GROUP
2	Private disks
3	Magnetic tape ACP

If the value of the bit is 1, the corresponding class of ACPs can be swapped. The value of decimal 15 (hexadecimal F---all bits on) enables swap for all classes of ACP. A value of decimal 14 disables swap for ACPs for volumes mounted with the /SYSTEM qualifier but leaves swap enabled for all other ACPs. Note that one has only disk ACPs present if they are specifically requested at mount time or if a Files-11 On-Disk Structure Level 1 disk is mounted. In general, only bit 3 is significant because usually no file ACPs exist.

ACP_SYSACC (A,D)

ACP_SYSACC sets the number of directory file control blocks (FCBs) that are cached for disks mounted with the /SYSTEM qualifier. Each directory FCB contains a 16-byte array containing the first letter of the last entry in each block of the directory (or group of blocks if the directory exceeds 16 blocks). Since entries in a directory are alphabetical, the cached FCB provides quick access to a required directory block. This parameter value should be roughly equivalent to the number of directories that are in use concurrently on each system volume. It might be overridden on a per-volume basis with the /ACCESSED qualifier to the DCL command MOUNT. The value should be kept low in systems with small physical memory and little file activity, because the FCBs require a significant amount of space in the nonpaged dynamic pool.

Too small a value causes excessive XQP I/O operations, while too large a value causes excessive physical memory to be consumed by the FCB caches.

ACP_WINDOW (D)

ACP_WINDOW sets the default number of window pointers to be allocated in a window for a default file access, for disks mounted with the /SYSTEM qualifier.

ACP_WORKSET (D)

ACP_WORKSET sets the default size of a working set for an ACP. A specification of 0 permits the ACP to calculate the size. This value should be nonzero only on small systems where memory is tight. Too small a value causes excessive ACP page, while too large a value causes excessive physical memory to be consumed by the ACP. Note that this parameter has no effect on the per-process XQP.

ACP_WRITEBACK (D)

ACP_WRITEBACK is a dynamic system parameter that controls whether deferred writes to file headers are enabled. The default value is 1, which enables deferred writes to file headers. To disable the feature, set ACP_WRITEBACK to 0.

This system parameter affects only applications like PATHWORKS that can request deferred writes to file headers. Note that the deferred write feature is not available on Files-11 ODS--1 volumes.

ACP_XQP_RES

ACP_XQP_RES controls whether the XQP is currently in memory. The default value (1) specifies that the XQP is permanently in memory. Change the default only on restricted memory systems with a small number of users and little or no file activity that requires XQP intervention. Such activity includes file opens, closes, directory lookups, and window turns.

AFFINITY_SKIP

AFFINITY_SKIP controls the breaking of implicit affinity. The value indicates the number of times a process is skipped before being moved.

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

AFFINITY_TIME

AFFINITY_TIME controls the breaking of implicit affinity. The value indicates how long a process remains on the compute queue.

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

ALLOCLASS

ALLOCLASS determines the device allocation class for the system. The device allocation class is used to derive a common lock resource name for multiple access paths to the same device.

ARB_SUPPORT (D)

(Alpha only) The Access Rights Block (ARB) compatibility option, the ARB_SUPPORT system parameter, is provided specifically to support products that have not yet been updated to use the new per-thread security Persona Security Block (PSB) data structure instead of the ARB. Changing the value of ARB_SUPPORT from 2 or 3 (the default) to any other value can affect the operation of these products.

Note HP recommends that all Version 7.3-1 systems have the ARB_SUPPORT parameter set to 3 (the default). Do not change the ARB_SUPPORT parameter to any other value until all products dependent on the ARB and associated structures have been modified for the new environment.

The following table describes ARB_SUPPORT parameters:

ARB_SUPPORT Parameter	Value	Behavior
ISS$C_ARB_NONE	0	The obsolete kernel data cells are not maintained by the system. Fields are initialized to zero (or set to invalid pointers) at process creation.
ISS$C_ARB_CLEAR	1	The obsolete kernel data cells are cleared (or set to invalid pointers) when the code would have set up values for backward compatibility.
ISS$C_ARB_READ_ONLY	2	The obsolete cells are updated with corresponding security information stored in the current PSB when a $PERSONA_ASSUME is issued.
ISS$C_ARB_FULL	3 (default)	Data is moved from the obsolete cells to the currently active PSB on any security-based operation.

AUTO_DLIGHT_SAV

AUTO_DLIGHT_SAV is set to either 1 or 0. The default is 0.

If AUTO_DLIGHT_SAV is set to 1, OpenVMS automatically makes the change to and from daylight saving time.

AWSMIN (D)

On VAX systems, AWSMIN establishes the lowest number of pages to which a working set limit can be decreased by automatic working set adjustment.

On Alpha systems, AWSMIN establishes the lowest number of pagelets to which a working set limit can be decreased by automatic working set adjustment.

AWSTIME (D)

AWSTIME specifies the minimum amount of processor time that must elapse for the system to collect a significant sample of a working set's page fault rate. The time is expressed in units of 10 milliseconds. The default value of 20, for example, is 200 milliseconds.

Some application configurations that have a large number of memory-intensive processes may benefit if the value is reduced. The value can be as low as 4.

AWSTIME expiration is checked only at quantum end. Reducing its value and not reducing QUANTUM effectively sets the value of AWSTIME equal to the value of QUANTUM.

BALSETCNT (A,G,M)

BALSETCNT sets the number of balance set slots in the system page table. Each memory-resident working set requires one balance set slot.

You can monitor the active system with the DCL command SHOW MEMORY or the MONITOR PROCESSES command of the Monitor utility to determine the actual maximum number of working sets in memory. If this number is significantly lower than the value of BALSETCNT, this parameter value may be lowered. If all balance set slots are being used, raise the value of BALSETCNT.

Never set BALSETCNT to a value higher than 2 less than MAXPROCESSCNT. If physical memory is a significant system constraint, consider lowering this value even further. However, if your system runs with a number of processes nearly equal to MAXPROCESSCNT, lowering BALSETCNT will force swapping to occur, which can affect system performance. Note that virtual balance slots (VBS) can affect the values of BALSETCNT and MAXPROCESSCNT.

BORROWLIM (A,D,M)

BORROWLIM defines the minimum number of pages required on the free-page list before the system permits process growth beyond the working set quota (WSQUOTA) for the process. This parameter should always be greater than FREELIM.

This parameter allows a process to grow beyond the value set by the working set quota (WSQUOTA) to the working set quota extent (WSEXTENT) on a system that has a substantial memory on the free-page list. This automatic working set adjustment also depends upon the values of parameters WSINC, PFRATH, and AWSTIME.

Working set growth attempts to alleviate heavy page faulting. To make use of this growth, you must also set the user's WSEXTENT authorization quota to a larger number than the WSQUOTA value.

BREAKPOINTS

If XDELTA is loaded, BREAKPOINTS enables additional built-in calls for XDELTA during the boot sequence. The breakpoints that are enabled may change from release to release of OpenVMS.

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

BUGCHECKFATAL (D)

BUGCHECKFATAL enables or disables the conversion of nonfatal bugchecks into fatal bugchecks. The system must be rebooted on a fatal bugcheck. A nonfatal bugcheck places an entry only in the error log and deletes the corresponding process.

This parameter should normally be OFF (0); you should set it ON (1) only when the executive is being debugged.

Setting the SYSTEM_CHECK parameter to 1 has the effect of setting BUGCHECKFATAL to ON (1).

BUGREBOOT (D)

BUGREBOOT enables or disables automatic rebooting of the system if a fatal bugcheck occurs. This parameter should normally be on (1); set it off (0) only when the executive is being debugged.

CHANNELCNT

CHANNELCNT specifies the number of permanent I/O channels available to the system.

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

CHECK_CLUSTER

(VAX only) CHECK_CLUSTER is the VAXCLUSTER parameter sanity check. When CHECK_CLUSTER is set to 1, SYSBOOT outputs a warning message and forces a conversational boot if it detects that the VAXCLUSTER parameter is set to 0.

CLASS_PROT (D)

CLASS_PROT performs the nondiscretionary classification checks. CLASS_PROT is also checked by XQP to determine if a classification block should be added to the header of any created files.

CLISYMTBL (D)

CLISYMTBL sets the size of the command interpreter symbol table, which controls the number of DCL symbols that can be created.

CLOCK_INTERVAL

(VAX only) CLOCK_INTERVAL sets the number of microseconds between the hardware interval timer clock interrupts. It has no effect on processors that have implemented only the subset interval clock registers.

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

CLUSTER_CREDITS

CLUSTER_CREDITS specifies the number of per-connection buffers a node allocates to receiving VMS$VAXcluster communications.

If the SHOW CLUSTER command displays a high number of credit waits for the VMS$VAXcluster connection, you might consider increasing the value of CLUSTER_CREDITS on the other node. However, in large cluster configurations, setting this value unnecessarily high consumes a large quantity of nonpaged pool. Each receive buffer is at least SCSMAXMSG bytes in size but might be substantially larger depending on the underlying transport.

It is not required for all nodes in the cluster to have the same value for CLUSTER_CREDITS.

The default value is currently 32. Unless a system has very constrained memory available, HP recommends that these values not be increased.

CONCEAL_DEVICES

CONCEAL_DEVICES enables or disables the use of concealed devices. By default, this parameter is set to enable concealed devices (1).

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

CRD_CONTROL

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

On VAX systems, CRD_CONTROL serves the function of CRDENABLE in earlier releases. On Alpha systems, CRD_CONTROL can be used to expand the function defined by CRDENABLE.

CRD_CONTROL is a bit mask for corrected read data (CRD) soft error control flags. These flags control the use of CRDERROR routines.

On VAX systems, the following bits are defined:

Bit	Description
0	Enables CRD processing for all systems.
1	Enables scrubbing (rewriting) of the memory location that induced the CRD.
2	Enables page replacement of the pages that exhibit repeated CRD errors.
3	Forces all memory pages to be included in the PFN database. On systems that contain more than 512 megabytes of memory, all memory is mapped by the PFN database by default. This bit allows the mapping to occur on systems with less than 512 megabytes of memory.

Default values are different for VAX and Alpha systems. On VAX systems, the default is 7, which enables CRD processing, scrubbing, and page replacement.

On Alpha systems, the following bits are defined:

Bit	Description
0	Enables CRD processing for all systems.
1	Enables scrubbing (rewriting) of the memory location that induced the CRD.
2	Enables page replacement of the pages that exhibit repeated CRD errors.
3	Forces all memory pages to be included in the PFN database. On systems that contain more than 512 megabytes of memory, all memory is mapped by the PFN database by default. This bit allows the mapping to occur on systems with less than 512 megabytes of memory.
4	Enables extended CRD handling, if available.
5	Enables loading of driver and process for handling server management events. Platform-specific code usually sets this bit if the required hardware and firmware support are available.
6	Disables CRD throttling.
16-31	Reserved for platform-specific error-handling control.

On Alpha systems, the default setting is 22, which enables scrubbing, page replacement, and extended CRD handling.

CRDENABLE

(Alpha only) CRDENABLE enables or disables detection and logging of memory-corrected read data (ECC) errors. This parameter should normally be set to (1).

Beginning with OpenVMS Version 7.2, CRD_CONTROL can expand the function of CRDENABLE. (Refer to CRD_CONTROL.)

CTLIMGLIM

CTLIMGLIM specifies the size of the default image I/O segment; that is channel table and initial buffer pool for image-related file and RMS I/O.

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

CTLPAGES (A)

CTLPAGES specifies the size of P1 pool. CTLPAGES is automatically changed only when the process logical name table, DCL symbols, or some layered products require an increase in the size of the P1 pool area.

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

CWCREPRC_ENABLE

CWCREPRC_ENABLE controls whether an unprivileged user can create a process on another OpenVMS Cluster node. The default value of 1 allows an unprivileged user to create a detached process with the same UIC on another node. A value of 0 requires that a user have DETACH or CMKRNL privilege to create a process on another node.

DBGTK_SCRATCH

(Alpha only) DBGTK_SCRATCH specifies how many pages of memory are allocated for the remote debugger. This memory is allocated only if remote debugging is enabled with the 8000 boot flag. Normally, the default value is adequate, but if the remote debugger issues an error message, you should increase this value. See Writing OpenVMS Alpha Device Drivers in C (Margie Sherlock and Lenny S. Szubowicz, Digital Press, 1996).

DCL_CTLFLAGS

DCL_CTLFLAGS is a bitmask used to alter default behavior for certain commands on a systemwide basis. At present, only the low bit of the bitmask is defined. The low bit controls the default process-name assignment for a subprocess created using the SPAWN command or LIB$SPAWN routine.

Prior to OpenVMS Version 7.3-1, if no process name was supplied, the system constructed a name by appending _n to the username, where n was the next available non-duplicate integer for any process currently in the system. For example, the first spawned process from user SYSTEM would be called SYSTEM_1, the second, SYSTEM_2, and so on. The next available number was chosen, as soon as a gap was found.

A problem with this technique is that determining the next available number is very expensive in terms of performance, because the mechanism attempts to create the process by incrementing names until one is found that unique. When several subprocesses already exist, the cost of creating the subprocess iteratively becomes even more expensive. When many processes are in the same OpenVMS group, the cost multiplies because process names must be unique throughout the group.

Beginning in OpenVMS Version 7.3-1, the default constructed process name for subprocesses has changed. Instead of incrementally searching for the next unique number, a random number is chosen to append to the username. Therefore, the first processes that are spawned from user SYSTEM might be SYSTEM_154, SYSTEM_42, SYSTEM_87, and so on. This procedure results in a very high probability of finding a unique name on the first try, because it is unlikely that the same number is already in use. This greatly reduces the cost of process creation, and applications that rely on spawned subprocesses might see a dramatic performance improvement due to this change.

However, some applications might rely on the previous method of assigning subprocess names. The DCL_CTLFLAGS parameter is available to allow you to configure the system as necessary.

Bit 0 of DCL_CTLFLAGS selects the behavior for assigning default subprocess names:

• If the bit is clear, the new behavior is used. If you do not specify a process name, the system assigns the username with a random number suffix. This is the default setting.
• If the bit is set, the prior behavior is used. If you do not specify a process name, the system assigns the username with a random number suffix.

DEADLOCK_WAIT (D)

DEADLOCK_WAIT defines the number of seconds that a lock request must wait before the system initiates a deadlock search on behalf of that lock. Setting DEADLOCK_WAIT to 0 disables deadlock checking. Setting DEADLOCK_WAIT to a value greater than 0 but still less than the default setting provides faster detection of deadlocks but requires more CPU usage.

DEFMBXBUFQUO (D)

DEFMBXBUFQUO sets the default for the mailbox buffer quota size in bytes when this value is not specified in a Create Mailbox ($CREMBX) system service call.

DEFMBXMXMSG (D)

DEFMBXMXMSG sets the default for the mailbox maximum message size in bytes when this value is not specified in a Create Mailbox ($CREMBX) system service call.

DEFPRI (D)

DEFPRI sets the base default priority for processes.

DEFQUEPRI (D)

DEFQUEPRI establishes the scheduling priority for jobs entered in batch and output (printer, server, and terminal) queues when no explicit scheduling priority is specified by the submitter. The value of this parameter can range from 0 to 255; the default value is 100.

The value of DEFQUEPRI should be less than or equal to MAXQUEPRI.

Note DEFQUEPRI refers to relative queue scheduling priority, not the execution priority of the job.

DELPRC_EXIT (D)

DELPRC_EXIT can be used to control $DELPRC system service options that call exit handlers prior to final cleanup and deletion of a process. The following table describes these options:

Option	Description
0	Disable the exit handler functionality with $DELPRC.
4	Execute kernel mode exit handlers.
5 (default)	Execute exec and more privileged mode exit handlers.
6	Execute supervisor and more privileged mode exit handlers.
7	Execute user and more privileged mode exit handlers.

DEVICE_NAMING

(Alpha only) DEVICE_NAMING is a bit mask indicating whether port allocation classes are used in forming SCSI device names.

Following is the bit definition:

Bit	Definition
0	If 1, enable new naming.
1	Must be 0. This bit is reserved for use by HP.

For more information about port allocation classes, see OpenVMS Cluster Systems.

DISABLE_UPCALLS (D)

DISABLE_UPCALLS is primarily a debugging aid. It allows the system manager to disable threads upcalls of specific types for the entire system. The value is a bit mask, with the bits corresponding to the upcall types. The upcall types are defined in the definition macro $TMCDEF.

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

DISK_QUORUM (D)

The DISK_QUORUM parameter is the name of an optional quorum disk in ASCII. ASCII spaces indicate that no quorum disk is being used.

DLCKEXTRASTK

(VAX only) DLCKEXTRASTK specifies the amount of extra interrupt stack (in bytes) to leave when doing a deadlock search.

This parameter is not used on Alpha systems.

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

DNVOSI1

DNVOSI1 is reserved to DECnet-Plus for OpenVMS. This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

DORMANTWAIT (D)

DORMANTWAIT specifies, in seconds, the amount of time that can elapse without a significant event before the system treats a low-priority computable process as a DORMANT process for scheduling purposes. (A low-priority process is a non real-time process whose current priority is equal to or less than the value specified by the system parameter DEFPRI [default=4].) After SUSP (suspended) processes, DORMANT processes are the most likely candidates for memory reclamation by the swapper.

Increasing the value of DORMANTWAIT can increase the interval that a low priority process blocks a high priority process if that low priority process is holding a lock or resource that the higher priority process is waiting for.

DR_UNIT_BASE (G)

(Alpha only) DR_UNIT_BASE specifies the base value from which unit numbers for DR devices (DIGITAL StorageWorks RAID Array 200 Family logical RAID drives) are counted.

DR_UNIT_BASE provides a way for unique RAID device numbers to be generated. DR devices are numbered starting with the value of DR_UNIT_BASE and then counting from there. For example, setting DR_UNIT_BASE to 10 produces device names such as $1$DRA10, $1$DRA11, and so on.

Setting DR_UNIT_BASE to appropriate, nonoverlapping values on all cluster members that share the same (nonzero) allocation class ensures that no two RAID devices are given the same name.

DUMPBUG

DUMPBUG enables (1) or disables (0) the writing of error log buffers and memory contents to SYS$SYSTEM:SYSDUMP.DMP when a fatal bugcheck occurs. This parameter should be off (0) only when the executive is being debugged.

DUMPSTYLE (A,D)

DUMPSTYLE specifies the method of writing system dumps.

DUMPSTYLE is a 32-bit mask, with the following bits defined. Each bit can be set independently. The value of the system parameter is the sum of the values of the bits that have been set. Remaining or undefined values are reserved for HP use only.

Bit	Mask	Description
0	00000001	0 =	Full dump (SYSGEN default). The entire contents of physical memory are written to the dump file.
		1 =	Selective dump. The contents of memory are written to the dump file selectively to maximize the usefulness of the dump file while conserving disk space.
1	00000002	0 =	Minimal console output.
		1 =	Full console output (includes stack dump, register contents, and so on).
2	00000004	0 =	Dump to system disk.
		1 =	Dump off system disk (DOSD) to an alternate disk. (Refer to the HP OpenVMS System Manager's Manual for details.)
3 (Alpha only) 1	00000008	0 =	Do not compress.
		1 =	Compress. (See note below.)
4 (Alpha only) 2	00000010	0 =	Dump shared memory.
		1 =	Do not dump shared memory. (See note below.)
5 - 14			Reserved for HP use only.
15 (VAX only) 3	00008000	0 =	Disable use of bits 16 - 27.
		1 =	Enable use of bits 16 - 27.
16 - 27 (VAX only) 2	0FFF0000		Range of DOSD unit numbers.
28 - 31			Reserved for HP use only.

If you plan to enable the Volume Shadowing minimerge feature on an Alpha system disk, be sure to specify DOSD to an alternate disk.

Examples:

The mask of 00000006 directs the system to send a full dump, with full console output, off the system disk (to the alternate disk).

For a VAX 7000, a mask of 00098006 directs the system to send a full dump with full console output to the DOSD whose unit number is 9.

On Alpha systems, the mask of 00000009 directs the system to compress a selective dump with minimal console output.

ERLBUFFERPAGES (A on Alpha)

On VAX systems, ERLBUFFERPAGES has a default value of 2 pages and a maximum value of 32 pages.

On Alpha systems, ERLBUFFERPAGES has a default value of 4 pagelets and a maximum value of 32 pagelets.

ERRORLOGBUFFERS

If you increase ERRORLOGBUFFERS, you must also increase the size of the system dump file.

EXPECTED_VOTES (A)

EXTRACPU (D)

EXUSRSTK

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

FAST_PATH

Starting in OpenVMS Version 7.2, FAST_PATH is enabled by default. In Versions 7.0 and 7.1, FAST_PATH was disabled by default.

For additional information, see FAST_PATH_PORTS and IO_PREFER_CPUS.

FAST_PATH_PORTS

FAST_PATH_PORTS is a 32-bit mask, with a bit assigned for each Fast Path port driver. The following table describes the bit values:

Beginning in OpenVMS Version 7.3-1, values of specific bit positions are those described in the following table:

Currently, the default setting for FAST_PATH_PORTS is 0, which means that Fast Path is enabled for all drivers that appear in the table.

In addition, note the following:

• CI drivers are not controlled by FAST_PATH_PORTS. Fast Path for CI is enabled and disabled exclusively by the FAST_PATH system parameter.
• FAST_PATH_PORTS is relevant only if the FAST_PATH system parameter is enabled (equal to 1). Setting FAST_PATH to zero has the same effect as setting all the bits in FAST_PATH_PORTS to 1.

For additional information, see FAST_PATH and IO_PREFER_CPUS. For an explanation of how to set the bits, see the HP OpenVMS I/O User's Reference Manual.

FREEGOAL (A,D,M)

FREELIM (A,M)

The system writes pages from the modified-page list, swaps out working sets, or reduces the size of the working sets to maintain the minimum count.

While the larger free-page list generally means less page I/O, it also means less space for the balance set, which tends to result in more swap I/O. You can monitor the size of the free-page list, the amount of page, and the amount of swap with the MONITOR IO command of the Monitor utility.

GALAXY

The default value is 0. GALAXY is not an AUTOGEN parameter.

GBLPAGES (A,D,F,G,M)

Users with CMKRNL privilege can change this parameter on a running system. Increasing the value of this parameter allows the global page table to expand, on demand, up to the maximum size.

The default value is sufficient for the images normally installed as shared in the system startup command procedures. Once the system is running and all global sections are created, you can examine the actual requirements with the /GLOBAL qualifier of the Install utility (INSTALL) and reduce the value of GBLPAGES accordingly. However, do not set the value of this parameter too low, because the page table entries use little permanently resident memory. If you plan to install many user images as shared, or if user programs are likely to create many global sections, you must increase the value of this parameter.

GBLPAGFIL (A,D)

Global page-file sections are created with the Create and Map Section system services ($CREATE_GPFILE, $CRMPSC, and $CRMPSC_GPFILE_64) without an explicit disk file. These sections are used for the RMS global buffers required for shared files. Users of shared files should note that global page-file sections cause both the global page table and the default system page file (PAGEFILE.SYS) to be used. If the value of GBLPAGFIL is too small, $CRMPSC issues an error message when you attempt to create global page-file sections.

You must have scratch global sections if you use RMS global buffers. Each file using global buffers requires, in the system page file, the file's bucket size multiplied by the number of global buffers for that file. If the file's bucket size varies, as with RMS indexed files, use the maximum bucket size. For shared sequential files, use the multiblock count of the first stream to perform the $CONNECT service in place of the file's bucket size.

The default value for this parameter is adequate for most systems. However, if your site uses RMS global buffering to a significant extent, you may need to raise the value of GBLPAGFIL. Use the /GLOBAL qualifier of the Install utility to examine the number of pages consumed by RMS global buffers. The global sections used by RMS for global buffers have the prefix RMS$ followed by 8 hexadecimal digits.

Global buffers are enabled with the DCL command SET FILE/GLOBAL_BUFFERS, which is described in the HP OpenVMS DCL Dictionary.

GBLSECTIONS (A,F,G,M)

The default value is sufficient for the images normally installed as shared in the system startup command procedures. Once the system is running and all global sections are created, you can examine the actual requirements with the /GLOBAL qualifier of the Install utility and reduce the value of GBLSECTIONS accordingly. However, the value of this parameter should not be set too low. If you plan to install many user images as shared, or if user programs are likely to create many global sections, you must increase the value of this parameter.

If the value of GBLSECTIONS is too small, you receive a message from the Install utility at system startup time or whenever you install images manually. Note that too large a value for GBLSECTIONS wastes physical memory.

GH_EXEC_CODE (A,F)

GH_EXEC_DATA (A,F)

GH_RES_CODE (A,F)

GH_RES_DATA (A,F)

If bit 2 of the LOAD_SYS_IMAGES parameter is set, the image LDR$WRAPUP releases all unused pages in the granularity hint region at the the end of system startup. The unused pages of the resident image granularity hint region are either reserved for future use, or given back to the free memory list.

GH_RSRVPGCNT (F)

If bit 2 of the LOAD_SYS_IMAGES parameter is set, the image LDR$WRAPUP releases all unused pages in the granularity hint region at the the end of system startup. The unused pages of the resident image granularity hint region are either reserved for future use, or given back to the free memory list.

GH_RSRVPGCNT specifies the number of pages that LDR$WRAPUP attempts to leave in the resident image code granularity hint region. If the GH_RSRVPGCNT number of pages is larger than the unused pages in the granularity hint region, the region is not expanded to accommodate the number of pages requested.

GLX_INST_TMO

The default is 20,000 milliseconds (20 seconds).

GLX_SHM_REG

GROWLIM (A,D,M)

IEEE_ADDRESS

IEEE_ADDRESSH

IJOBLIM (D)

IMGIOCNT

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

IMGREG_PAGES

For more information, see the INSTALL section in the HP OpenVMS System Management Utilities Reference Manual.

INTSTKPAGES (A,D,G,M)

Use the default value of 6 unless interrupt-stack-not-valid exceptions occur. These may be caused by either an unusually large number of devices or a driver that requires a large amount of stack space.

IO_PREFER_CPUS

IO_PREFER_CPUS is a CPU bit mask specifying the CPUs that are allowed to serve as preferred CPUs and that can thus be assigned a Fast Path port. CPUs whose bit is set in the IO_PREFER_CPUS bit mask are enabled for Fast Path port assignment. IO_PREFER_CPUS defaults to -1, which specifies that all CPUs are allowed to be assigned Fast Path ports.

You might want to disable the primary CPU from serving as a preferred CPU by clearing its bit in IO_PREFER_CPUS. This reserves the primary CPU for non-Fast-Path IO operations to use.

Changing the value of IO_PREFER_CPUS causes the FASTPATH_SERVER process to execute the automatic assignment algorithm that spreads Fast Path ports evenly among the new set of usable CPUs.

For additional information, see FAST_PATH and FAST_PATH_PORTS.

IOTA

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

JBOBLIM

JOBCTLD

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

KFILSTCNT

KSTACKPAGES

LAMAPREGS (G)

LAN_FLAGS (D)

The bit definitions are as follows:

LCKMGR_CPUID

If the specified CPU ID is either the primary CPU or a nonexistent CPU, the LCKMGR_SERVER process utilizes the lowest nonprimary CPU. For more information, refer to the LCKMGR_MODE system parameter.

LCKMGR_MODE

The Dedicated CPU Lock Manager performs all locking operations on a single dedicated CPU. This can improve system performance on large SMP systems with high MP_Synch associated with the lock manager.

If the number of active CPUs is greater than or equal to LCKMGR_MODE, a LCKMGR_SERVER process is created to service locking operations. This process runs at a real-time priority of 63 and is always current.

In addition, if the number of active CPUs should ever be reduced below the required threshold by either a STOP/CPU command or by a CPU reassignment in a Galaxy configuration, the Dedicated CPU Lock Manager automatically turns off within one second, and the LCKMGR_SERVER is placed in a hibernate state. If the number of active CPUs is increased, the LCKMGR_SERVER resumes servicing locking operations.

Specify one of the following:

• Zero (0) indicates that the Dedicated CPU Lock Manager is off (the default).
• A number greater than zero (0) indicates the number of CPUs that must be active before the Dedicated CPU Lock Manager will turn on.

For more information about use of the Dedicated CPU Lock Manager, see the OpenVMS Performance Management.

LGI_BRK_DISUSER (D)

LGI_BRK_LIM (D)

The minimum value is 1. The default value is usually adequate.

LGI_BRK_TERM (D)

Ordinarily, LGI_BRK_TERM should be set to off (0) when physical terminal names are created dynamically, such as when network protocols like LAT and Telnet are in use.

LGI_BRK_TMO (D)

LGI_CALLOUTS (D)

LGI_HID_TIM (D)

LGI_PWD_TMO (D)

LGI_RETRY_LIM (D)

LGI_RETRY_TMO (D)

LNMPHASHTBL (A on VAX,G)

LNMSHASHTBL (A,F,G)

LOAD_PWD_POLICY

LOAD_SYS_IMAGES (A on Alpha)

LOAD_SYS_IMAGES controls the loading of system images described in the system image data file, VMS$SYSTEM_IMAGES. This parameter is a bit mask.

On VAX systems, the following bit is defined:

On Alpha systems, the following bits are defined:

These bits are on by default. Using conversational bootstrap exec slicing can be disabled.

LOCKDIRWT (A)

LOCKIDTBL (A,F,M)

For simple timesharing systems, the default value is adequate. If your application uses many locks, as in the case of heavy RMS file sharing or a database management application, you should increase this parameter. When you change the value of LOCKIDTBL, examine the value of RESHASHTBL and change it if necessary.

The OpenVMS Lock Management facility is described in the OpenVMS Programming Concepts Manual. You can monitor locks with the MONITOR LOCK command of the Monitor utility.

LOCKIDTBL_MAX

LOCKRETRY

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

LONGWAIT (A on Alpha,D,G,M)

MAXBOBMEM (D)

Other MAXBOB* parameters are obsolete beginning in OpenVMS Version 7.3.

MAXBUF (D)

The number of bytes specified in the I/O request plus the size of a driver-dependent and function-dependent header area determine the required buffered I/O packet size. The size of the header area is a minimum of 16 bytes; there is no absolute upper limit. However, this header area is usually a few hundred bytes in size.

On OpenVMS VAX systems beginning with Version 7.1, the default value is 4112. The default value on OpenVMS Alpha systems continues to be 8192.

The maximum value of MAXBUF is 64000 bytes.

MAXCLASSPRI (D)

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

MAXPROCESSCNT (A,F,G,M)

The default value is normally configured to allow you to create the desired number of processes. If the following message appears, you need to increase the value of MAXPROCESSCNT:

%SYSTEM-F-NOSLOT,  No PCB to create process

MAXQUEPRI (D)

MAXSYSGROUP (D)

MC_SERVICES_P0 (D)

A value of 1 causes other nodes in the MEMORY CHANNEL cluster to crash with bugcheck code MC_FORCED_CRASH if this node bugchecks or shuts down.

The default value is 0. A setting of 1 is intended only for debugging purposes; the parameter should otherwise be left at its default value.

MC_SERVICES_P1 (D)

MC_SERVICES_P2

PMDRIVER is a driver that serves as the MEMORY CHANNEL cluster port driver. It works together with MCDRIVER (the MEMORY CHANNEL device driver and driver interface) to provide MEMORY CHANNEL clustering. If PMDRIVER is not loaded, cluster connections are not made over the MEMORY CHANNEL interconnect.

The default value is 1, which causes PMDRIVER to be loaded when you boot the system. When you run CLUSTER_CONFIG.COM and select the MEMORY CHANNEL option, PMDRIVER is loaded automatically when you reboot the system.

HP recommends that this value not be changed. This parameter value must be the same on all nodes connected by MEMORY CHANNEL.

MC_SERVICES_P3 (D)

The default value is 800. HP recommends that this value not be changed. This parameter value must be the same on all nodes connected by MEMORY CHANNEL.

MC_SERVICES_P4

The default value is 200. HP recommends that this value not be changed. This parameter value must be the same on all nodes connected by MEMORY CHANNEL.

MC_SERVICES_P5 (D)

MC_SERVICES_P6

The default value is 992. This value is suitable in all cases except for systems with highly constrained memory. For such systems, you can reduce the memory consumptions of MEMORY CHANNEL by slightly reducing the default value of 992. The value of MC_SERVICES_P6 must always be equal to or greater than the result of the following calculations:

1. Select the larger of SCS_MAXMSG and SCS_MAXDG.
2. Round that value up to the next quadword.

The value of MC_SERVICES_P6 must be the same on all nodes connected by MEMORY CHANNEL.

MC_SERVICES_P7 (D)

• A value of 0 indicates nonverbose mode: no informational messages appear on the console or in the error log.
• A value of 1 indicates verbose mode: informational messages from both MCDRIVER and PMDRIVER appear on the console and in the error log.
• A value of 2 provides the same output as a value of 1, with the addition of PMDRIVER stalling and recovery messages.

The default value is 0. HP recommends that this value not be changed except while debugging MEMORY CHANNEL problems or adjusting the MC_SERVICES_P9 parameter.

MC_SERVICES_P8

MC_SERVICES_P9

Note that MC_SERVICES_P9 is not a dynamic parameter; you must reboot the system after each change for that change to take effect.

The default value is 150. HP recommends that this value not be changed.

The value of MC_SERVICES_P9 must be the same on all nodes connected by MEMORY CHANNEL.

MINCLASSPRI (D)

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

MINWSCNT (A)

On VAX systems, MINWSCNT sets the minimum number of fluid pages (pages not locked in the working set) required for the execution of a process. The value of MINWSCNT must provide sufficient space to execute any VAX instruction. Theoretically, the longest instruction requires 52 pages; however, all code can run with 20 fluid pages. An insufficient value may inhibit system performance or even put a process into an infinite loop on some instructions.

On Alpha systems, MINWSCNT sets the minimum number of pages required for the execution of a process. The default value is 20; the minimum value is 10.

MMG_CTLFLAGS (A,D)

The following bit mask values are defined:

MPDEV_AFB_INTVL

MPDEV_POLLER must be set to ON to enable automatic failback. You can disable automatic failback without disabling the poller by setting MPDEV_AFB_INTVL to 0. The default is 300 seconds.

MPDEV_D*

MPDEV_ENABLE

MPDEV_REMOTE and MPDEV_AFB_INTVL have no effect when MPDEV_ENABLE is set to OFF.

MPDEV_LCRETRIES

MPDEV_POLLER

MPDEV_REMOTE

To use multipath failover to a served path, MPDEV_REMOTE must be enabled on all systems that have direct access to shared SCSI/Fibre Channel devices. The first release to provide this feature is OpenVMS Alpha Version 7.3--1. Therefore, all nodes on which MPDEV_REMOTE is enabled must be running OpenVMS Alpha Version 7.3--1 (or later).

If MPDEV_ENABLE is set to OFF (0), the setting of MPDEV_REMOTE has no effect because the addition of all new paths to multipath sets is disabled. The default is ON.

MPW_HILIMIT (A,G)

If MPW_HILIMIT is too low, excessive page faulting can occur from the page file. If it is too high, too many physical pages can be consumed by the modified-page list.

If you increase MPW_HILIMIT, you might also need to increase MPW_WAITLIMIT. Note that if MPW_WAITLIMIT is less than MPW_HILIMIT, a system deadlock occurs. The values for the two parameters are usually equal.

MPW_IOLIMIT (A on Alpha)

MPW_LOLIMIT (A,G)

MPW_LOLIMIT ensures that a certain number of pages are available on the modified-page list for page faults. If the number is too small, the caching effectiveness of the modified-page list is reduced. If it is too high, less memory is available for processes, so that swap (and page) may increase.

MPW_LOWAITLIMIT (A,D)

MPW_PRIO

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

MPW_THRESH (A on Alpha,D)

MPW_WAITLIMIT (A,D)

MPW_WRTCLUSTER (A,G)

If MPW_WRTCLUSTER is too small, it takes many I/O operations to empty the modified-page list. If MPW_WRTCLUSTER is too large for the speed of the disk that holds the page file, other I/O operations are held up for the modified-page list write.

On VAX systems, the MPW_WRTCLUSTER default value and maximum value is 120 512-byte pages; its minimum value is 16 512-byte pages.

On Alpha systems, the MPW_WRTCLUSTER default value is 64 8192-byte pages; its maximum value is 512 8192-byte pages; and its minimum value is 16 8192-byte pages.

MSCP_BUFFER (A,F)

On VAX systems, MSCP_BUFFER specifies the number of pages to be allocated to the MSCP server's local buffer area.

On Alpha systems, MSCP_BUFFER specifies the number of pagelets to be allocated to the MSCP server's local buffer area.

MSCP_CMD_TMO (D)

The MSCP_CMD_TMO default value of 0 is normally adequate. A value of 0 provides the same behavior as in previous releases of OpenVMS (which did not have an MSCP_CMD_TMO system parameter). A nonzero setting increases the amount of time before an MSCP command times out.

If command timeout errors are being logged on client nodes, setting the parameter to a nonzero value on OpenVMS servers reduces the number of errors logged. Increasing the value of this parameter reduces the numb client MSCP command timeouts and increases the time it takes to detect faulty devices.

If you need to decrease the number of command timeout errors, HP recommends that you set an initial value of 60. If timeout errors continue to be logged, you can increase this value in increments of 20 seconds.

MSCP_CREDITS

The default value is currently 32. Unless a system has very constrained memory available, HP recommends that these values not be increased.

MSCP_LOAD (A)

MSCP_SERVE_ALL

Starting with OpenVMS Version 7.2, the serving types are implemented as a bit mask. To specify the type of serving your system will perform, locate the type you want in the following table and specify its value. For some systems, you may want to specify two serving types, such as serving the system disk and serving locally attached disks. To specify such a combination, add the values of each type, and specify the sum.

In a mixed-version cluster that includes any systems running OpenVMS Version 7.1-x or earlier, serving all available disks is restricted to serving all disks except those whose allocation class does not match the system's node allocation class (pre-Version 7.2). To specify this type of serving, use the value 9 (which sets bit 0 and bit 3).

The following table describes the serving type controlled by each bit and its decimal value:

Although the serving types are now implemented as a bit mask, the values of 0, 1, and 2, specified by bit 0 and bit 1, retain their original meanings:

0 --- Do not serve any disks (the default for earlier versions of OpenVMS).
1 --- Serve all available disks.
2 --- Serve only locally attached (non-HSx and non-DSSI) disks.

If the MSCP_LOAD system parameter is 0, MSCP_SERVE_ALL is ignored.

MULTIPROCESSING

Specify one of the following values:

Setting the SYSTEM_CHECK parameter to 1 has the effect of setting MULTIPROCESSING to 2.

MULTITHREAD (A)

The maximum value for MULTITHREAD is 256.

MVSUPMSG_INTVL (D)

The system issues a mount verification message after a sequence of MVSUPMSG_NUM mount verifications have gone unannounced on a specific fibre channel disk device within a span of MVSUPMSG_INTVL seconds.

If this parameter is zero, all mount verification messages are announced.

MVSUPMSG_NUM (D)

The system issues a mount verification message after a sequence of MVSUPMSG_NUM mount verifications have gone unannounced on a specific fibre channel disk device within a span of MVSUPMSG_INTVL seconds.

If this parameter is zero, all mount verification messages are announced.

MVTIMEOUT (A on Alpha,D)

NET_CALLOUTS (D)

NISCS_CONV_BOOT

NISCS_LAN_OVRHD

NISCS_LOAD_PEA0

NISCS_MAX_PKTSZ (A on Alpha)

NISCS_MAX_PKTSZ allows the system manager to change the packet size used for cluster communications on network communication paths. PEDRIVER automatically allocates memory to support the largest packet size that is usable by any virtual circuit connected to the system up to the limit set by this parameter. Its default values are different for OpenVMS Alpha and OpenVMS VAX:

• On Alpha, to optimize performance, the default value is the largest packet size currently supported by OpenVMS.
• On VAX, to conserve memory, the default value is the Ethernet packet size.

PEDRIVER uses NISCS_MAX_PKTSZ to compute the maximum amount of data to transmit in any LAN packet:

LAN packet size <= LAN header (padded Ethernet format)
                   + NISCS_MAX_PKTSZ
                   + NISCS checksum (only if data checking
                                     is enabled)
                   + LAN CRC or FCS

The actual packet size automatically used by PEDRIVER might be smaller than the NISCS_MAX_PKTSZ limit for any of the following reasons:

• On a per-LAN path basis, if PEdriver determines that the LAN path between two nodes, including the local and remote LAN adapters and intervening LAN equipment, can only convey a lesser size.
  In other words, only nodes with large-packet LAN adapters connected end-to-end by large-packet LAN equipment can use large packets. Nodes connected to large-packet LANs but having an end-to-end path that involves an Ethernet segment restrict packet size to that of an Ethernet packet (1498 bytes).
• For performance reasons, PEDRIVER might further limit the upper bound on packet size so that the packets can be allocated from a lookaside list in the nonpaged pool.

The actual memory allocation includes the required data structure overhead used by PEDRIVER and the LAN drivers, in addition to the actual LAN packet size.

The following table shows the minimum NISCS_MAX_PKTSZ value required to use the maximum packet size supported by specified LAN types:

NISCS_PORT_SERV (A)

Starting with OpenVMS Version 7.3-1, you can use the SCACP command SET VC/CHECKSUMMING to specify data checking on the VCs to certain nodes. You can do this on a running system. (Refer to the SCACP documentation in this manual for more information.)

Changing the setting of NISCS_PORT_SERV, on the other hand, requires a reboot. Furthermore, this parameter applies to all virtual circuits between the node on which it is set and other nodes in the cluster.

NJOBLIM (D)

NOAUTOCONFIG (D)

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

NOCLUSTER

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

NOPGFLSWP

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

NPAGECALC

HP sets the default value of NPAGECALC to 1 only during the initial boot after an installation or upgrade. When the value of NPAGECALC is 1, the system calculates an initial value for the NPAGEVIR and NPAGEDYN system parameters. This calculated value is based on the amount of physical memory in the system.

NPAGECALC's calculations do not reduce the values of NPAGEVIR and NPAGEDYN from the values you see or set at the SYSBOOT prompt. However, NPAGECALC's calculation might increase these values.

AUTOGEN sets NPAGECALC to 0. NPAGECALC should always remain 0 after AUTOGEN has determined more refined values for the NPAGEDYN and NPAGEVIR system parameters.

NPAGEDYN (A,F,G,M)

To set a value for this parameter, use AUTOGEN initially, and then monitor the amount of space actually used with the DCL command SHOW MEMORY/POOL/FULL.

For the benefit of OpenVMS VAX systems with limited physical memory, AUTOGEN logs a warning message in its report if NPAGEDYN exceeds 10 percent of physical memory or if NPAGEVIR exceeds 33 percent of physical memory.

AUTOGEN also limits its own calculated value for NPAGEDYN to 20 percent of physical memory and limits NPAGEVIR to 50 percent of physical memory. These calculated values are adequate for most workstations and systems with 16 or fewer megabytes of physical memory. If your system requires a larger value, you can override the AUTOGEN calculated values by setting higher values in MODPARAMS.DAT.

NPAGERAD (G)

Also notice that the OpenVMS system might round the specified values higher to an even number of pages for each RAD, which prevents the base RAD from having too little nonpaged pool. For example, if the hardware is an AlphaServer GS160 with 4 RADs:

NPAGEDYN = 6291456 bytes
NPAGERAD = 2097152 bytes

In this case, the OpenVMS system allocates a total of approximately 6,291,456 bytes of nonpaged pool. Of this amount, the system divides 2,097,152 bytes among the RADs that are not the base RAD. The system then assigns the remaining 4,194,304 bytes to the base RAD.

On AlphaServer GS series processors on OpenVMS systems prior to Version 7.3-1, system managers frequently saw pool expansion that increasing NPAGEDYN did not reduce. This problem was caused by leaving NPAGERAD at its default value of 0.

Starting in OpenVMS Version 7.3-1, when NPAGERAD is 0 (the default), the system calculates a value to use for NPAGERAD with the following formula:

                  Base RAD memory
   NPAGEDYN * (1- --------------- )
                   Total memory

This calculation gives more pool to the non-base RADs than before and, therefore, reduces the expansion of non-base RADs.

NPAGEVIR (A, G)

For the benefit of OpenVMS VAX systems with limited physical memory, AUTOGEN logs a warning message in its report if NPAGEDYN exceeds 10 percent of physical memory or if NPAGEVIR exceeds 33 percent of physical memory.

AUTOGEN also limits its own calculated value for NPAGEDYN to 20 percent of physical memory, and limits NPAGEVIR to 50 percent of physical memory. These calculated values are adequate for most workstations and systems with 16 or fewer megabytes of physical memory. If your system requires a larger value, you can override the AUTOGEN calculated values by setting higher values in MODPARAMS.DAT.

NPAG_AGGRESSIVE (D)

NPAG_BAP_MAX

See also NPAG_BAP_MIN.

NPAG_BAP_MAX_PA

NPAG_BAP_MIN

NPAG_BAP_MIN_PA

NPAG_GENTLE (D)

NPAG_INTERVAL (D)

NPAG_RING_SIZE

PAGEDYN (A,F,G,M)

The paged dynamic pool is used to allocate storage for shared logical names, resident image headers, known file list entries, and RMS file-sharing structures. Substantial amounts of space for the pool can be overallocated with little effect on system performance.

The size of the paged pool can grow dynamically up to the maximum size that this parameter specifies.

PAGFILCNT (G)

PAGTBLPFC

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

PAMAXPORT (D)

A system does not detect the existence of ports whose port numbers are higher than this parameter's value. Thus, set this parameter to a value that is equal to or greater than the highest port number being used on any CI or DSSI connected to the system.

You can decrease this parameter to reduce polling activity if the hardware configuration has fewer than 16 ports. For example, if the CI or DSSI with the largest configuration has a total of 5 ports assigned to port numbers 0 through 4, you could set PAMAXPORT to 4.

If CI or DSSI devices are not configured on your system, this parameter is ignored.

The default for this parameter is 15 (poll for all possible ports 0 through 15). HP recommends that you set this parameter to the same value on each cluster computer.

PANOPOLL (D)

PANOPOLL is functionally equivalent to uncabling the system from the DSSI or star coupler. This parameter does not affect OpenVMS Cluster communications by LAN.

The default value of 0 is the normal setting and is required if you are booting from an HSC controller or if your system is joining an OpenVMS Cluster. This parameter is ignored if no CI or DSSI devices are configured on your system.

PANUMPOLL (D)

On systems with less powerful CPUs, the parameter may be useful in applications sensitive to the amount of contiguous time that the system spends at IPL 8. Reducing PANUMPOLL reduces the amount of time spent at IPL 8 during each polling interval, while increasing the number of polling intervals needed to discover new or failed ports.

If CI or DSSI devices are not configured on your system, this parameter is ignored.

PAPOLLINTERVAL (D)

This parameter trades polling overhead against quick response to virtual circuit failures. HP recommends that you use the default value for this parameter.

HP recommends that you set this parameter to the same value on each cluster computer.

PAPOOLINTERVAL (D)

This parameter trades faster response to pool allocation failures against increased polling overhead. HP recommends that you use the default value for this parameter.

If CI or DSSI devices are not configured on your system, this parameter is ignored.

PASANITY (D)

PASANITY is normally set to 1 and should be set to 0 only when you are debugging with XDELTA or planning to halt the CPU for periods of 100 seconds or more.

PASANITY is only semidynamic. A new value of PASANITY takes effect on the next CI or DSSI port reinitialization.

If CI or DSSI devices are not configured on your system, this parameter is ignored.

PASTDGBUF (A)

Memory Channel devices ignore this parameter.

PASTIMOUT (D)

If CI or DSSI devices are not configured on your system, this parameter is ignored.

The default value should always be adequate.

PE*

PFCDEFAULT (A,D)

On Alpha systems during execution of programs, PFCDEFAULT controls the number of image pagelets read from disk per I/O operation when a page fault occurs. The PFCDEFAULT maximum default value is 2032 512-byte pagelets (127 8192-byte Alpha pages).

The read I/O operations can take place from an image file or from the page file. The actual size of the cluster can be less than PFCDEFAULT, depending on the size of image sections and the pattern of page references.

The value should not be greater than one-fourth the default size of the average working set to prevent a single page fault from displacing a major portion of a working set. Too large a value for PFCDEFAULT can hurt system performance. PFCDEFAULT can be overridden on an image-by-image basis with the CLUSTER option of the OpenVMS linker.

PFN_COLOR_COUNT

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so. If you increase this parameter, you must also increase the ZERO_LIST_HI system parameter.

PFRATH (A on Alpha,D,M)

On VAX systems, the default value is 120 page faults every 10 seconds.

On Alpha systems, the default value is 8 page faults every 10 seconds.

PFRATL (A,D,M)

Increasing the value of this parameter tends to decrease the limits of the working sets, while decreasing its value tends to increase their limits.

PHYSICAL_MEMORY (A)

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

PHYSICALPAGES (A)

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

PIOPAGES (A,D)

Beginning with OpenVMS Version 7.2, the default value has been raised to 575. The setting has been raised to accommodate the increased demands for process-permanent memory that result from changes made to RMS file-naming parsing in Version 7.2.

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

PIXSCAN (A,D)

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

POOLCHECK (D)

POOLCHECK is used to investigate frequent and inexplicable failures in a system. When POOLCHECK is enabled, pool-checking routines execute whenever pool is deallocated or allocated.

Two loadable forms of SYSTEM_PRIMITIVES.EXE are available at boot time. The default image, which contains no pool-checking code and no statistics maintenance, is loaded when POOLCHECK is set to zero. When POOLCHECK is set to a nonzero value, the monitoring version of SYSTEM_PRIMITIVES.EXE, which contains both pool-checking code and statistics maintenance, is loaded.

Setting the SYSTEM_CHECK parameter to 1 has the effect of setting POOLCHECK to %X616400FF. For further information about pool checking, refer to the OpenVMS VAX Device Support Manual (archived but available on the OpenVMS Documentation CD-ROM).

POOLCHECK is a DYNAMIC parameter. However, for a change in its value to have any effect, POOLCHECK must be non-0 at boot time (to load the monitoring version of SYSTEM_PRIMITIVES.EXE).

POOLPAGING

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

POWEROFF (D)

If firmware or hardware support for the power-off request is not implemented, the shut-down procedure will leave the system halted but fully powered.

PQL_DASTLM (D,G)

PQL_DBIOLM (D,G)

PQL_DBYTLM (D,G)

PQL_DCPULM (D,G)

The default value of 0 imposes no limit on CPU time usage and is typically the correct value for this parameter.

PQL_DDIOLM (D,G)

PQL_DENQLM (D,G)

PQL_DFILLM (D,G)

PQL_DJTQUOTA (D)

PQL_DPGFLQUOTA (A on VAX,D,G)

PQL_DPRCLM (D,G)

PQL_DTQELM (D,G)

PQL_DWSDEFAULT (A,G)

PQL_DWSEXTENT (A,D,G)

PQL_DWSQUOTA (A,D,G)

PQL_MASTLM (D,G)

PQL_MBIOLM (D,G)

PQL_MBYTLM (D,G)

PQL_MCPULM (D,G)

PQL_MDIOLM (D,G)

PQL_MENQLM (D,G)

PQL_MFILLM (D,G)

PQL_MJTQUOTA (D)

PQL_MPGFLQUOTA (A on VAX,D,G)

On Alpha systems, PQL_MPGFLQUOTA sets the minimum pagelet file quota for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process).

PQL_MPRCLM (D,G)

PQL_MTQELM (D,G)

PQL_MWSDEFAULT (A,G)

This value overrides a smaller quantity that is set for a user in AUTHORIZE.

PQL_MWSEXTENT (A,D,G)

This value overrides a smaller quantity set for a user in AUTHORIZE.

PQL_MWSQUOTA (A,D,G)

This value overrides a smaller quantity set for a user in AUTHORIZE.

PRCPOLINTERVAL (A on Alpha,D)

This parameter trades polling overhead against quick recognition of new systems or servers as they appear.

PRIORITY_OFFSET

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

PROCSECTCNT (A,G)

Set a value greater than the maximum number of image sections in any section to be run, as indicated by the linkage memory allocation map for the image.

PSEUDOLOA

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

PU_OPTIONS

QBUS_MULT_INTR

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

QDSKINTERVAL

QDSKVOTES

QUANTUM (A on Alpha,D,M)

• Processor time: maximum amount of processor time a process can receive before control passes to another process of equal priority that is ready to compute
• Balance set residency: minimum amount of service a compute-state process must receive before being swapped out to secondary storage

RAD_SUPPORT (G)

Bits are defined in the RAD_SUPPORT parameter as follows:

RAD_SUPPORT (default is 79; bits 0-3 and 6 are set)
___________________________________________________

 3   2 2   2 2         1 1
 1   8 7   4 3         6 5         8 7         0
+-----+-----+-----------+-----------+-----------+
|00|00| skip|ss|gg|ww|pp|00|00|00|00|0p|df|cr|ae|
+-----+-----+-----------+-----------+-----------+

Bit 0 (e): Enable    - Enables RAD support

Bit 1 (a): Affinity  - Enables Soft RAD Affinity (SRA) scheduling
                       Also enables the interpretation of the skip
                       bits, 24-27.

Bit 2 (r): Replicate - Enables system-space code replication

Bit 3 (c): Copy      - Enables copy on soft fault

Bit 4 (f): Fault     - Enables special page fault allocation
                       Also enables the interpretation of the
                       allocation bits, 16-23.

Bit 5 (d): Debug     - Reserved to HP

Bit 6 (p): Pool      - Enables per-RAD non-paged pool

Bits 7-15:           - Reserved to HP

Bits 16-23:          - If bit 4 is set, bits 16-23 are interpreted
                       as follows:

Bits 16,17 (pp): Process = Pagefault on process (non global)
                           pages
Bits 18,19 (ww): Swapper = Swapper's allocation of pages for
                           processes
Bits 20,21 (gg): Global  = Pagefault on global pages
Bits 22,23 (ss): System  = Pagefault on system space pages

Encodings for pp, ww, gg, ss:
Current  (0) - allocate PFNs from the current CPU's RAD
Random   (1) - allocate PFNs using the "random" algorithm
Base     (2) - allocate PFNs from the operating system's "base" RAD
Home     (3) - allocate PFNs from the current process's home RAD

If bits 16-23 are 0, the defaults for pp, ww, gg, ss are interpreted
as follows:

    Process = home RAD
    Swapper = current RAD (also sets home RAD for process)
    Global  = random RAD
    System  = base RAD

Bits 24-27:   - If bit 1 is set, bits 24-27 are interpreted
                as a skip count value (power of 2). Example: If
                bits 24-27 contain a 3, the skip count is 8.
                If bits 24-27 contain a 5, the skip count is 32.
                If bits 24-27 are 0, the default of 16 is used
                as the skip count.

Bits 28-31:   - Reserved to HP

For more information about using OpenVMS RAD features, see the OpenVMS Alpha Galaxy and Partitioning Guide.

REALTIME_SPTS (D,G,M)

RECNXINTERVAL (A on Alpha,D)

RESALLOC

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

RESHASHTBL (A,F,M)

RJOBLIM (D)

RMS_CONPOLICY (D)

Possible values are the following:

You can set this system parameter with the DCL command SET RMS_DEFAULT/SYSTEM/CONTENTION_POLICY=value and display the parameter with the DCL command SHOW RMS_DEFAULT.

RMSD* (D)

RMS_DFLRL (D)

RMS_DFMBC (A,D)

You can set this system parameter with the DCL command SET RMS_DEFAULT/SYSTEM and display the parameter with the SHOW RMS_DEFAULT command.

RMS_DFMBFIDX (A,D)

You can set this system parameter with the DCL command SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_DEFAULT.

RMS_DFMBFREL (A,D)

You can set this system parameter with the DCL command SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_DEFAULT.

RMS_DFMBFSDK (A,D)

The default value is usually adequate. However, if read-ahead or write-behind operations are used, a larger number improves performance.

You can set this system parameter with the DCL command SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_DEFAULT.

RMS_DFMBFSMT (A,D)

You can set this system parameter with the DCL command SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_DEFAULT.

RMS_DFMBFSUR (A,D)

You can set this system parameter with the DCL command SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_DEFAULT.

RMS_DFNBC (A,D)

The network block count value represents the number of blocks that RMS is prepared to allocate for the I/O buffers used to transmit and receive data. The buffer size used for remote file access, however, is the result of a negotiation between RMS and the remote file access listener (FAL). The buffer size chosen is the smaller of the two sizes presented.

Thus, RMS_DFNBC places an upper limit on the network buffer size that is used. It also places an upper limit on the largest record that can be transferred to or from a remote file. In other words, the largest record that can be transferred must be less than or equal to RMS_DFNBC multiplied by 512 bytes.

You can set this system parameter with the DCL command SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_DEFAULT.

RMS_EXTEND_SIZE (D)

When small disk quotas are used, specify a small number such as the disk cluster size to prevent the user's disk quota from being consumed. If the value of 0 is used, RMS allocates large extents and truncates the file back to its actual usage when it closes.

You can set this system parameter with the DCL command SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_DEFAULT.

RMS_FILEPROT

Because a process always inherits its default file protection from its creator process, RMS_FILEPROT determines default file protection only for users who do not execute the DCL command SET PROTECTION/DEFAULT in their login command procedures or during interactive sessions.

The protection is expressed as a mask. (See the discussion of the $CRMPSC system service in the HP OpenVMS System Services Reference Manual for more information about specifying protection masks.) By default, the mask is 64000 (decimal) or FA00 (hexadecimal), which represents the following protection:

You can set this system parameter with the DCL command SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_DEFAULT.

RMS_HEURISTIC (D)

RMS_PROLOGUE (D)

RMS_SEQFILE_WBH (D)

RSRVPAGCNT

On VAX systems, RSRVPAGCNT sets the number of pages that are reserved and escrowed for the current process page file.

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

S0_PAGING

• Setting bit 0 disables paging of all Exec code and data.
• Setting bit 1 disables paging of all RMS code and data.

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

S2_SIZE

SA_APP

SAVEDUMP

SBIERRENABLE

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

SCH_CTLFLAGS (D)

Beginning in OpenVMS Version 7.3-1, the default value for SCH_CTLFLAGS is 1.

SCSBUFFCNT (A,F,G)

On Alpha systems, the system communication services (SCS) buffers are allocated as needed, and SCSBUFFCNT is reserved for HP use only.

SCSCONNCNT

SCSFLOWCUSH (D)

The default value is adequate on most systems. If a systems communication architecture (SCA) port is not configured on your system, this parameter is ignored.

SCSI_NOAUTO (D)

SCSI_NOAUTO prevents the loading of a disk or tape SCSI class driver for any given device ID in a configuration that includes a SCSI third-party device. The SCSI_NOAUTO system parameter stores a bit mask of 32 bits, where the low-order byte corresponds to the first SCSI bus (PKA0), the second byte corresponds to the second SCSI bus (PKB0), and so on, as follows:

For each SCSI bus, setting the low-order bit inhibits automatic configuration of the device with SCSI device ID 0; setting the second low-order bit inhibits automatic configuration of the device with SCSI device ID 1, and so forth. For instance, the value 00002000_16 prevents the device with SCSI ID 5 on the bus identified by SCSI port ID B from being configured. By default, all the bits in the mask are cleared, allowing all devices to be configured.

SCSICLUSTER_P[1-4]

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

SCSMAXDG (G)

SCSMAXMSG (G)

SCSNODE (A,G)

Specify SCSNODE as a string of up to six characters. Enclose the string in quotation marks.

If the computer is in an OpenVMS Cluster, specify a value that is unique within the cluster. Do not specify the null string.

If the computer is running DECnet for OpenVMS, the value must be the same as the DECnet node name.

SCSRESPCNT (A,F,G)

If SCA or DSA ports are not configured on your system, the system ignores SCSRESPCNT.

SCSSYSTEMID (G)

If the computer is in an OpenVMS Cluster, specify a value that is unique within the cluster. Do not use zero as the value.

If the computer is running DECnet for OpenVMS, calculate the value from the DECnet address using the following formula:

SCSSYSTEMID = ((DECnet area number) * 1024) + (DECnet node number)

Example: If the DECnet address is 2.211, calculate the value as follows:

SCSSYSTEMID = (2 * 1024) + 211 = 2259

SCSSYSTEMIDH (G)

SECURITY_POLICY

The following bits are defined:

The default value of 7 preserves compatibility with existing DECwindows Motif behavior. A value of 0 disables all unevaluated configurations.

SETTIME

SHADOW_D1-D5

SHADOWING

Specify one of the following values:

SHADOW_MAX_COPY (A,D)

Carefully consider the needs of each shadowed node when you set this parameter. Too high a value for SHADOW_MAX_COPY can affect performance by allowing too many copy threads to operate in parallel. Too low a value unnecessarily restricts the number of threads your system can effectively handle.

See HP Volume Shadowing for OpenVMS for more information about setting system parameters for volume shadowing.

SHADOW_MAX_UNIT

On OpenVMS Alpha systems, the default value for this system parameter is 500, which consumes 24KB of main memory. On OpenVMS VAX systems, the default value is 100, which consumes 5KB of main memory.

If you do not plan to use Volume Shadowing for OpenVMS, you can change the setting to its minimum of 10 (which consumes 480 bytes of main memory). Setting the default to its minimum frees up 23.5KB of main memory on an OpenVMS Alpha system and 4.5KB of main memory on a VAX system. (The maximum value of this parameter is 10,000.)

This system parameter is not dynamic; that is, a reboot is required when you change the setting.

SHADOW_MBR_TMO (D)

The SHADOW_MBR_TMO parameter is valid for use only with Phase II of Volume Shadowing for OpenVMS. You cannot set this parameter for use with Phase I, which is obsolete.

Use the SHADOW_MBR_TMO parameter (a word) to specify the number of seconds, in decimal from 1 to 65,535, during which recovery of a repairable shadow set is attempted. If you do not specify a value or if you specify 0, the default delay of 120 seconds is used.

Because SHADOW_MBR_TMO is a dynamic parameter, you should use the SYSGEN command WRITE CURRENT to permanently change its value.

SHADOW_REC_DLY (D)

SHADOW_SITE_ID (D)

The system manager can now define the site value to be used for all shadow sets mounted on a system. This parameter is an arbitrary numeric value coordinated by the system manager of disaster tolerant clusters. Reads from devices that have site values matching the shadow set's site value are preferred over reads from devices with different site values. For detailed information, see the description of the $SET DEVICE/SITE in the HP OpenVMS DCL Dictionary and HP Volume Shadowing for OpenVMS.

SHADOW_SYS_DISK

Also specify a system disk shadow set virtual unit number with the SHADOW_SYS_UNIT system parameter, unless the desired system disk unit number is DSA0.

To enable minimerge on a system disk, add the value 4096 to your existing SHADOW_SYS_DISK value. For example, if you have SHADOW_SYS_DISK set to a value of 1, change it to 4097 to enable minimerge. Also, be sure to set the DUMPSTYLE parameter to dump off system disk, as described in the HP OpenVMS System Manager's Manual.

SHADOW_SYS_TMO

• At system boot time, when this is the first node in the cluster to boot and to create this specific shadow set. If the proposed shadow set is not currently mounted in the cluster, use this parameter to extend the time a booting system waits for all former members of the shadowed system disk to become available.
• Once the system successfully mounts the virtual unit and begins normal operations. In this usage, the SHADOW_SYS_TMO parameter controls the time the operating system waits for errant members of a system disk. (Use the SHADOW_MBR_TMO parameter to control the time the operating system waits for the errant members of an application disk.)

This parameter applies only to members of the system disk shadow set. All nodes using a particular system disk shadow set should have their SHADOW_SYS_TMO parameter set to the same value once normal operations begin.

The default value is 120 seconds. Change this parameter to a higher value if you want the system to wait more than the 120-second default for all members to join the shadow set. You can set the parameter value to 120 through 65,535 seconds.

SHADOW_SYS_UNIT

SHADOW_SYS_WAIT

The default value is 480 seconds. Change this parameter to a higher value if you want the system to wait more than the 480-second default for all members to join the shadow set. You can set the parameter value to 1 through 65,535 seconds.

SMCI_FLAGS (D)

Bits in the bit mask are the following:

SMCI_PORTS

Loading additional ports allows multiple paths between Galaxy instances. In the initial release of the Galaxy software, having multiple communications channels is not an advantage because SYS$PBDRIVER does not support fast path. A future release of OpenVMS will provide Fast Path support for SYS$PBDRIVER, when multiple CPUs improve throughput by providing multiple communications channels between instances.

SMP_CPUS

The default value of SMP_CPUS, --1, boots all available CPUs into the multiprocessing system.

Note that although a bit in the mask corresponds to the primary processor's CPU ID, the primary processor is always booted. That is, if the mask is set to 0, the primary CPU still boots. Any available secondary processors are not booted into the multiprocessing system.

This parameter is ignored if the MULTIPROCESSING parameter is set to 0.

SMP_CPUSH

SMP_LNGSPINWAIT

The default value is 3000000 (3 million 10-microsecond intervals or 30 seconds).

SMP_SANITY_CNT

The default value is 300 milliseconds (30 10-millisecond intervals).

SMP_SPINWAIT

A timeout causes a CPUSPINWAIT bugcheck.

The default value is 100000 (100,000 10-microsecond intervals or 1 second).

SMP_TICK_CNT

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

SPTREQ (A)

Executive image
RMS image
SYSMSG.EXE file
Multiport memory structures
Each MASSBUS adapter
Each UNIBUS adapter
Each DR32 adapter

The number of system page table entries required for all other purposes is automatically computed and added to the value of SPTREQ to yield the actual size of the system page table.

SSINHIBIT

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

STARTUP_P1--8

SWP_PRIO

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

SWPALLOCINC

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

SWPFAIL

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

SWPFILCNT

SWPOUTPGCNT (A on VAX,D)

On VAX systems, SWPOUTPGCNT defines the minimum number of pages to which the swapper should attempt to reduce a process before swapping it out. The pages taken from the process are placed into the free-page list.

On Alpha systems, SWPOUTPGCNT defines the minimum number of pagelets to which the swapper should attempt to reduce a process before swapping it out. The pagelets taken from the process are placed into the free-page list.

SWPRATE

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

SYSMWCNT (A,G,M)

While a high value takes space away from user working sets, a low value can seriously impair system performance. Appropriate values vary, depending on the level of system use. When the system is running at full load, check the rate of system faults with the MONITOR PAGE command of the Monitor utility. An average system page fault rate of between 0 and 3 page faults per second is desirable. If the system page fault rate is high, and especially if the system seems to be slow, you should increase the value of SYSMWCNT. However, do not set this parameter so high that system page faulting never occurs.

SYSPFC

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

SYSTEM_CHECK

Enabling SYSTEM_CHECK causes the system to behave as if the following system parameter values are set (although the values of the following parameters are not actually changed):

While SYSTEM_CHECK is enabled, the previous settings of the BUGCHECKFATAL and MULTIPROCESSING parameters are ignored. However, setting the parameter POOLCHECK to a nonzero value overrides the setting imposed by SYSTEM_CHECK.

Setting SYSTEM_CHECK creates certain image files that are capable of the additional system monitoring. These image files are located in SYS$LOADABLE_IMAGES and can be identified by the suffix _MON. For information about the type of data checking performed by SYSTEM_CHECK, see the description of the ACP_DATACHECK parameter. For information about the performance implications of enabling SYSTEM_CHECK, see OpenVMS Performance Management.

On VAX systems, SYSTEM_CHECK is a special parameter, which is subject to change at any time and should be modified only if recommended by HP.

TAILORED

TAPE_ALLOCLASS

The TAPE_ALLOCLASS parameter can also be used to generate a unique clusterwide name for tape devices with identical unit numbers.

TAPE_MVTIMEOUT (D)

TBSKIPWSL

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

TIME_CONTROL (D)

TIME_CONTROL is an SMP bit mask parameter that controls debugging functions. The following bits are defined:

TIMEPROMPTWAIT

Depending on the value specified for the TIMEPROMPTWAIT parameter, the system acts in one of the following ways:

• If TIMEPROMPTWAIT is 0, no prompt or wait occurs; the system boots immediately, using the time of the last boot as the system time.
• If TIMEPROMPTWAIT is a positive number less than 32768, one prompt is issued and the value dictates how many seconds you can take to respond with a time. If you do not provide a time before TIMEPROMPTWAIT elapses, the system boots, using the time of the last boot as the system time.
• If TIMEPROMPTWAIT is a number in the range of 32768 through 65535, the prompt for the time is issued at intervals starting with 2 and doubling until 256 seconds is reached. If no response is received, the prompts restart, with the 2-second interval. This prompting process repeats indefinitely, until you specify a time.

TIMVCFAIL (D)

TMSCP_LOAD (A)

Setting TMSCP_LOAD to 0 inhibits the loading of the tape server and the serving of local tapes. Setting TMSCP to 1 loads the tape server into memory at the time the system is booted and makes all directly connected tape drives available clusterwide. The following table describes the two states of the TMSCP_LOAD parameter:

TMSCP_SERVE_ALL

Starting with OpenVMS Version 7.2, the serving types are implemented as a bit mask. To specify the type of serving your system will perform, locate the type you want in the following table and specify its value. For some systems, you may want to specify two serving types, such as serving all tapes except those whose allocation class does not match. To specify such a combination, add the values of each type, and specify the sum.

In a mixed-version cluster that includes any systems running OpenVMS Version 7.1-x or earlier, serving all available tapes is restricted to serving all tapes except those whose allocation class does not match the system's allocation class (pre-Version 7.2 meaning). To specify this type of serving, use the value 9, which sets bit 0 and bit 3. The following table describes the serving type controlled by each bit and its decimal value:

Although the serving types are now implemented as a bit mask, the values of 0, 1, and 2, specified by bit 0 and bit 1, retain their original meanings:

• 0 --- Do not serve any tapes (the default for earlier versions of OpenVMS).
• 1 --- Serve all available tapes.
• 2 --- Serve only locally attached (non-HSx and non-DSSI) tapes.

If the TMSCP_LOAD system parameter is 0, TMSCP_SERVE_ALL is ignored.

TTY_ALTALARM

TTY_ALTYPAHD

The default value is usually adequate. Do not exceed the maximum value of 32767 when setting this parameter.

TTY_AUTOCHAR (D)

TTY_BUF

TTY_CLASSNAME

TTY_DEFCHAR

Where a condition is false, the value is 0.

The upper byte is the page length. The default characteristics are 24 lines per page, terminal synchronization, wraparound, lowercase, scope, and full-duplex.

TTY_DEFCHAR2

The defaults are AUTOBAUD and EDITING.

TTY_DEFPORT

TTY_DIALTYPE

TTY_DMASIZE (D)

TTY_PARITY

TTY_RSPEED

TTY_SCANDELTA

TTY_SILOTIME

TTY_SPEED

TTY_TIMEOUT (D)

TTY_TYPAHDSZ

UAFALTERNATE (G,M)

UDABURSTRATE (G)

USERD1 (D)

On Alpha systems, this symbol is in the SYS$LOADABLE_IMAGES:SYS$BASE_IMAGE module.

On VAX systems, the symbol is in the SYS$SYSTEM:SYS.STB module.

USERD2 (D)

On Alpha systems, this symbol is in the SYS$LOADABLE_IMAGES:SYS$BASE_IMAGE module.

On VAX systems, the symbol is in the SYS$SYSTEM:SYS.STB module.

USER3

On Alpha systems, this symbol is in the SYS$LOADABLE_IMAGES:SYS$BASE_IMAGE module.

On VAX systems, the symbol is in the SYS$SYSTEM:SYS.STB module.

USER4

On Alpha systems, this symbol is in the SYS$LOADABLE_IMAGES:SYS$BASE_IMAGE module.

On VAX systems, the symbol is in the SYS$SYSTEM:SYS.STB module.

VAXCLUSTER (A)

The default value is 1.

VBN_CACHE_S

The static system parameter VBN_CACHE_S enables or disables file system data caching. By default its value is 1, which means that caching is enabled and the Virtual I/O Cache is loaded during system startup.

Setting the value to 0 disables file system data caching on the local node and throughout the OpenVMS Cluster. In an OpenVMS Cluster, none of the other nodes in the cluster can cache any file data until this node either leaves the cluster or reboots with VBN_CACHE_S set to 1.

VBSS_ENABLE (A)

This parameter enables virtual balance slots (VBS) to be created. A virtual balance slot holds the mapping for a memory-resident process that does not currently own a real balance slot (RBS). The set of real balance slots is timeshared among all memory-resident processes. With VBS enabled, the quantity of memory-resident processes is limited by the system parameter MAXPROCESSCNT. With VBS disabled, the quantity of memory-resident processes is limited by the system parameter BALSETCNT.

When creating a new process, if the set of real balance slots is allocated, then a virtual balance slot is created and the owner of a real balance slot is selected and transitioned to the virtual balance slot. The new process is created in the real balance slot. Processes are transitioned (faulted) back to a real balance slot as they are scheduled to execute on a CPU.

VBSS_ENABLE2

This cell is used for enabling and disabling VBS dynamic capabilities that are valid only when VBS is enabled. The following table indicates the result for each value:

VCC_FLAGS (A)

VCC_MAXSIZE (A)

The virtual I/O cache cannot shrink or grow. Its size is fixed at system startup.

To adjust the XFC size, use the VCC_MAX_CACHE system parameter.

VCC_MAX_CACHE (D)

The Extended File Cache can automatically shrink and grow, depending on your I/O workload and how much spare memory your system has. As your I/O workload increases, the cache automatically grows, but never to more than the maximum size. When your application needs memory, the cache automatically shrinks.

The value of VCC_MAX_CACHE at system startup sets an upper limit for the maximum size of the Extended File Cache. You cannot increase the maximum size of VCC_MAX_CACHE beyond its value at boot time. For example, if VCC_MAX_CACHE is 60 MB at system startup, you can then set VCC_MAX_CACHE to 40, which decreases the maximum size to 40 MB. If you then set VCC_MAX_CACHE to 80, the maximum size is only increased to 60 MB, the value set at system startup.

Note that VCC_MAX_CACHE is a semi-dynamic parameter. If you change its value, you must enter the DCL command SET CACHE/RESET for any changes to take effect immediately. Otherwise, it might take much more time for the changes to take effect.

If you are using the reserved memory registry to allocate memory permanently, you must set the VCC$MIN_CACHE_SIZE entry in the reserved memory registry to a value less than or equal to VCC_MAX_CACHE at system startup time.

Refer to the HP OpenVMS System Manager's Manual for instructions on setting permanent memory allocations for the cache.

VCC_MAX_IO_SIZE (D)

Changing the value of VCC_MAX_IO_SIZE affects reads and writes to volumes currently mounted on the local node, as well as reads and writes to volumes mounted in the future.

If VCC_MAX_IO_SIZE is 0, the Extended File Cache on the local node cannot cache any reads or writes. However, the system is not prevented from reserving memory for the Extended File Cache during startup if a VCC$MIN_CACHE_SIZE entry is in the reserved memory registry.

VCC_MAX_LOCKS

VCC_MINSIZE

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

VCC_PTES

The virtual I/O cache automatically shrinks and grows, depending on your I/O workload and how much spare memory your system has. As your I/O workload increases, the cache automatically grows, but never to more than the maximum size. When your applications need memory, the cache automatically shrinks.

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

VCC_READAHEAD (D)

By default VCC_READAHEAD is 1, which means that the Extended File Cache can use read-ahead caching. The Extended File Cache detects when a file is being read sequentially in equal-sized I/Os, and fetches data ahead of the current read, so that the next read instruction can be satisfied from cache.

To stop the Extended File Cache from using read-ahead caching, set VCC_READAHEAD to 0.

Changing the value of VCC_READAHEAD affects volumes currently mounted on the local node, as well as volumes mounted in the future.

Readahead I/Os are totally asynchronous from user I/Os and only take place if sufficient system resources are available.

VCC_WRITEBEHIND

VCC_WRITE_DELAY

VECTOR_MARGIN (D)

The default value of the VECTOR_MARGIN parameter is 200_10 .

VECTOR_PROC

This parameter is not used on Alpha systems.

VIRTUALPAGECNT (A,G,M)

If you use SYS$UPDATE:LIBDECOMP.COM to decompress libraries and the VIRTUALPAGECNT setting is low, make sure you set the PGFLQUOTA field in the user authorization file to at least twice the size of the library.

At installation time, AUTOGEN automatically sets an appropriate value for VIRTUALPAGECNT. The value depends on the particular configuration---the type and number of graphics adapters on the system, if any exist. You cannot set VIRTUALPAGECNT below the minimum value required for your graphics configuration.

Because the VIRTUALPAGECNT setting supports hardware address space rather than system memory, do not use the value of VIRTUALPAGECNT that AUTOGEN sets to gauge the size of your page file.

Starting with OpenVMS Version 7.0, VIRTUALPAGECNT has been an obsolete parameter on Alpha systems. Note, however, that the parameter remains in existence on Alpha systems for compatibility purposes and has a default and maximum value of %X7FFFFFFF. SYSBOOT and AUTOGEN enforce this default value.

VMS*

VOTES (A)

WBM_MSG_INT (D)

In single-message mode, WBM_MSG_INT is the time interval in milliseconds between assessments of the most suitable write bitmap message mode. In single-message mode, the writes issued by each remote node are, by default, sent one by one in individual SCS messages to the node with the master write bitmap. If the writes sent by a remote node reach an upper threshhold of messages during a specified interval, single-message mode switches to buffered-message mode.

In buffered-message mode, WBM_MSG_INT is the maximum time a message waits before it is sent. In buffered-message mode, the messages are collected for a specified interval and then sent in one SCS message. During periods of increased message traffic, grouping multiple messages to send in one SCS message to the master write bitmap is generally more efficient than sending each message separately.

The minimum value of WBM_MSG_INT is 10 milliseconds. The maximum value is -1, which corresponds to the maximum positive value that a longword can represent. The default is 10 milliseconds.

WBM_MSG_LOWER (D)

WBM_MSG_LOWER is the lower threshold for the number of messages sent during the test interval that initiates single-message mode. In single-message mode, the writes issued by each remote node are, by default, sent one by one in individual SCS messages to the node with the master write bitmap. If the writes sent by a remote node reach an upper threshhold of messages during a specified interval, single-message mode switches to buffered-message mode.

The minimum value of WBM_MSG_LOwer is 0 messages per interval. The maximum value is -1, which corresponds to the maximum positive value that a longword can represent. The default is 10.

WBM_MSG_UPPER (D)

WBM_MSG_UPPER is the upper threshold for the number of messages sent during the test interval that initiates buffered-message mode. In buffered-message mode, the messages are collected for a specified interval and then sent in one SCS message.

The minimum value of WBM_MSG_UPPER is 0 messages per interval. The maximum value is -1, which corresponds to the maximum positive value that a longword can represent. The default is 100.

WBM_OPCOM_LVL (D)

WINDOW_SYSTEM (D)

WLKSYSDSK

WPRE_SIZE (D)

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

WPTTE_SIZE (D)

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

WRITABLESYS

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

WRITESYSPARAMS (D)

On Alpha systems, WRITESYSPARAMS indicates that parameters are modified during SYSBOOT and are written out to ALPHAVMSSYS.PAR by STARTUP.COM.

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

WSDEC (A,D,M)

On VAX systems, WSDEC specifies the number of pages by which the limit of a working set is automatically decreased at each adjustment interval (which is quantum end). At a setting of 35, for example, the system decreases the limit of a working set by 35 pages each time a decrease is required.

On Alpha systems, WSDEC specifies the number of pagelets by which the limit of a working set is automatically decreased at each adjustment interval (which is quantum end). At a setting of 35, for example, the system decreases the limit of a working set by 35 pagelets each time a decrease is required.

WSINC (A on Alpha,D,M)

On VAX systems, WSINC specifies the number of pages by which the limit of a working set is automatically increased at each adjustment interval (which is quantum end). At a setting of 150, for example, the system increases the limit of a working set by 150 pages each time an increase is required. On VAX systems, the default value is 150 512-byte pages.

On Alpha systems, WSINC specifies the number of pagelets by which the limit of a working set is automatically increased at each adjustment interval (which is quantum end). At a setting of 150, for example, the system increases the limit of a working set by 150 pagelets each time an increase is required. On Alpha systems, the default value is 2400 512-byte pagelets (150 8192-byte Alpha pages).

A value of 0 for WSINC disables the automatic adjustment of working set limits for all processes. Limits stay at their base values. You can disable the automatic adjustment of working set limits on a per-process basis by using the DCL command SET WORKING_SET.

WSMAX (A,G,M)

This is intended to assist managers of systems that host large numbers of users whose working sets are not large. Systems whose user bases consist of a small number of users (or processes) that require large amounts of physical memory (for example, simulations) might need to set MIN_WSMAX to a value that satisfies the requirements of those processes.

WS_OPA0

XFMAXRATE (D)

XQPCTL2

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

XQPCTLD1

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

ZERO_LIST_HI (A,D)