Understanding Booting and System Startup

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HP OpenVMS System Manager's Manual, Volume 1:...

Starting Up and Shutting Down the System

Booting with Modified System Parameter Values

Understanding Booting and System Startup

Booting is the process of loading system software from the system disk into processor memory. When you boot your system, it automatically performs a series of tasks to start up your system. These tasks are collectively known as system startup.

You must have installed the operating system before you boot the system for the first time.

Booting procedures vary for different computers. For example, computers with console storage devices use a boot command procedure. You can copy and edit this command procedure to specify the location of the system disk. Other computers have an internal memory device that provides the name of the system disk.

On Alpha systems, you cannot boot from a magnetic tape device.

Booting and Startup Processes

Together, the booting and startup processes comprise the following steps:

You enter the BOOT command. The boot block, a fixed location on disk, points to the primary bootstrap image, which is loaded from disk into main memory.

On VAX systems, the primary bootstrap image is VMB.EXE.

On Alpha systems, the primary bootstrap image is APB.EXE.

The primary bootstrap image allows access to the system disk by finding the secondary bootstrap image, SYS$SYSTEM:SYSBOOT.EXE, and loading it into memory.

SYSBOOT.EXE loads the system parameters stored in the default parameter file into memory. (For more information about the default parameter file and loading of system parameters at boot time, see Booting with Modified System Parameter Values.)

If you are performing a conversational boot, the procedure stops and displays the SYSBOOT> prompt. (For information about conversational booting, see Conversational Boot: For Special Booting Functions.) Otherwise, SYSBOOT.EXE loads the operating system executive into memory and transfers control to the executive.

When the executive finishes, it executes the SWAPPER process.

The SWAPPER creates the SYSINIT process.

Among other actions it performs, SYSINIT creates the STARTUP process.

STARTUP executes SYS$SYSTEM:STARTUP.COM (unless you indicated another file using SYSMAN, SYSGEN, or conversational boot). STARTUP.COM executes a series of other startup command procedures, including SYSTARTUP_VMS.COM. (For more information about STARTUP.COM, see System Startup and STARTUP.COM. For more information about other startup procedures, see Understanding Site-Specific Startup Command Procedures.)

The current values of system parameters are written back to the default parameter file.

The boot process finishes, and you can log in to the operating system.

Deferring Memory Testing on AlphaServer 4100 Computers

To speed up the time between system power-on and user login, you can now defer a portion of memory testing on AlphaServer 4100 computers. When you choose this option, the console tests a minimum amount of memory and leaves the rest for the operating system to test.

To use this new feature, you need to specify a value for the MEMORY_TEST environment variable at the console before booting. The values for MEMORY_TEST are the following:

Value Description

FULL (off)
The console does all the testing.

NONE
32 MB of memory are tested before booting.

PARTIAL
256 MB of memory are tested before booting.

Value	Description
FULL (off)	The console does all the testing.
NONE	32 MB of memory are tested before booting.
PARTIAL	256 MB of memory are tested before booting.

If you set MEMORY_TEST to NONE or PARTIAL, OpenVMS tests any remaining untested memory on an as-needed basis at either or both of the following times:

While the operating system is booting

In the scheduler idle loop when no processes are available to run

When you change the value of MEMORY_TEST, you must issue the INIT console command before the new value takes effect. Therefore, you need to follow these steps from the console before booting:

Change the value of MEMORY_TEST (if desired).

Issue the INIT command from the console.

Boot the operating system.

OpenVMS also gives you more control over when memory is actually tested. Bit 2 in the system parameter MMG_CTLFLAGS controls deferred memory testing:

If the bit is clear (the default), OpenVMS tests memory in the background and not necessarily before the bootstrap process has completed.

If you set the bit, OpenVMS guarantees that all memory will be tested by the end of EXEC_INIT in the system bootstrap process; that is, before IPL is lowered from 31.

Types of Booting Operations

You can perform the following types of booting operations:

Type Purpose For More Information

Nonstop boot
To boot without stopping to perform special operations. Use this kind of boot in most cases.
Nonstop Boot: The Most Common Booting Operation

Conversational boot
To perform special boot operations--for example, to change system parameters before booting.
Conversational Boot: For Special Booting Functions

Type	Purpose	For More Information
Nonstop boot	To boot without stopping to perform special operations. Use this kind of boot in most cases.	Nonstop Boot: The Most Common Booting Operation
Conversational boot	To perform special boot operations--for example, to change system parameters before booting.	Conversational Boot: For Special Booting Functions

Nonstop Boot: The Most Common Booting Operation

The most common boot operation is a nonstop boot from the system disk. You perform a nonstop boot after changing certain system parameters or installing certain layered products, or after a standalone backup.

Follow the instructions for a nonstop boot in either of the following manuals:

On VAX systems, refer to the most recent versions of the OpenVMS VAX Upgrade and Installation Manual and the upgrade and installation supplement for your VAX computer.

On Alpha systems, refer to the HP OpenVMS Alpha Version 7.3-2 Upgrade and Installation Manual.

Conversational Boot: For Special Booting Functions

A conversational boot is used in programming research and development environments where you must alter operating conditions for experimentation, testing, and debugging. Use a conversational boot to perform the following operations:

Operation For More Information¹

Boot after showing or modifying individual system parameter values.
Booting After Showing or Modifying Individual System Parameter Values

Boot using system parameter values from an alternate parameter file.
Booting with an Alternate System Parameter File

Boot with default values for system parameters; for example, when modified system parameter values have caused the system to become unbootable.
Booting with Default System Parameters

Boot without running startup or login procedures; for example, when modified startup or login procedures have caused the system to become unbootable.
Booting Without Startup and Login Procedures

Boot without the user authorization file; for example, when the user authorization file has been modified so that you cannot log in.
Booting Without the User Authorization File

Boot with an alternate site-independent startup procedure.
Booting with an Alternate Site-Independent Startup Procedure

Boot with a minimum startup.
Booting with Minimum Startup

Display startup procedure commands while booting.
Booting While Displaying Startup Procedure Commands

Operation	For More Information¹
Boot after showing or modifying individual system parameter values.	Booting After Showing or Modifying Individual System Parameter Values
Boot using system parameter values from an alternate parameter file.	Booting with an Alternate System Parameter File
Boot with default values for system parameters; for example, when modified system parameter values have caused the system to become unbootable.	Booting with Default System Parameters
Boot without running startup or login procedures; for example, when modified startup or login procedures have caused the system to become unbootable.	Booting Without Startup and Login Procedures
Boot without the user authorization file; for example, when the user authorization file has been modified so that you cannot log in.	Booting Without the User Authorization File
Boot with an alternate site-independent startup procedure.	Booting with an Alternate Site-Independent Startup Procedure
Boot with a minimum startup.	Booting with Minimum Startup
Display startup procedure commands while booting.	Booting While Displaying Startup Procedure Commands

To boot your system conversationally, follow the instructions for a conversational boot in either of the following manuals:

On VAX systems, refer to the most recent versions of the OpenVMS VAX Upgrade and Installation Manual and the upgrade and installation supplement for your VAX computer.

On Alpha systems, refer to the HP OpenVMS Alpha Version 7.3-2 Upgrade and Installation Manual.

System Startup and STARTUP.COM

Immediately after your system boots, it runs the site-independent command procedure SYS$SYSTEM:STARTUP.COM to start up the system and control the sequence of startup events. This section describes STARTUP.COM.

Do not modify SYS$SYSTEM:STARTUP.COM. This file is deleted and replaced each time you upgrade your system to the next version of the operating system. Leaving STARTUP.COM intact prevents you from inadvertently altering any commands in the file, which in turn could cause the startup procedure to fail.

Although you should not modify STARTUP.COM, sometimes you may want to control site-independent startup when booting your system. For information, see Booting with Controlled Startup.

STARTUP.COM uses a series of command procedures, executable images, and database files to perform the following startup tasks:

Define systemwide logical names required for the symbolic debugger, language processors, linker, image activator, and help processor.

Start processes that control error logging, SMISERVER (the system management server), the job controller, the operator log file, and security auditing.

Connect devices that are physically attached to the system by invoking the SYCONFIG.COM procedure. Configure devices and load their I/O drivers.

STARTUP.COM creates the CONFIGURE process only on a full boot. If external devices are needed on any other boot (such as a minium or an upgrade boot), add the following line to SYS$MANAGER:SYLOGICALS.COM:

$IF P1 .NES. "FULL" THEN @SYS$SYSTEM:STARTUP CONFIGURE

Install known images to reduce I/O overhead in activating the most commonly run images or to identify images that must have special privileges.

STARTUP.COM executes the following site-specific startup command procedures in this order:

SYS$MANAGER:SYCONFIG.COM

SYS$MANAGER:SYLOGICALS.COM

SYS$MANAGER:SYPAGSWPFILES.COM

SYS$MANAGER:SYSECURITY.COM

SYS$MANAGER:SYSTARTUP_VMS.COM

For information about site-specific startup command procedures, see Modifying Site-Specific Startup Command Procedures.

Messages Indicating Booting and Startup Progress

When you successfully boot a system, it prints a banner, followed by messages similar to the following message:

The following message indicates that the system is executing the command procedure SYS$SYSTEM:STARTUP.COM:
```
The OpenVMS system is now executing the system startup procedure.
```
This procedure configures and initializes the system and executes several site-specific command procedures. For more information, see System Startup and STARTUP.COM.

A short time later (up to a few minutes), the system displays a message similar to the following message:
```
The OpenVMS system is now executing the site-specific system startup commands.
```
This message indicates that the system is executing SYSTARTUP_VMS.COM. You can modify this file to perform various operations at startup time. For more information, see Modifying SYSTARTUP_VMS.COM to Perform General Operations.

Finally, the procedure displays informational messages and accounting information. For example:

%SET-I-INTSET, login interactive limit=64, current interactive value = 0
19-APR-2000 15:00:00.00
  SYSTEM       job terminated at 19-APR-2000 15:00:00.00
                                                  
Accounting information:
 Buffered I/O count:       133     Peak working set size:        401
 Direct I/O count:          12     Peak pagefile size:          2379
 Page faults:              325     Mounted volumes:                0
 Charged CPU time: 0 00:00:55.23   Elapsed time:       0 00:01:31.24

After the system displays this information, you can log in.

Footnotes

1 In most cases, HP recommends that you use AUTOGEN to modify system parameters. In special cases, however, you can use a conversational boot to modify a parameter value temporarily. To change a parameter value permanently, you must edit MODPARAMS.DAT and run AUTOGEN. For instructions, see HP OpenVMS System Manager's Manual, Volume 2: Tuning, Monitoring, and Complex Systems.

( Number takes you back )

Booting with Modified System Parameter Values