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

Using Files and Directories

Copying and Transferring Files

Understanding Hard Links

Creating a CD-ROM  

Read and write-once support for CD-R and CD-RW drives was introduced in OpenVMS Alpha Version 7.3-1 on the AlphaServer DS25 system. OpenVMS supports only qualified CD-R and CD-RW drives. For more information on Alpha and I64 systems and the drives they support, refer to the appropriate page at the following Web site:

http://h18002.www1.hp.com/hps/buy.html#configure

You can create a CD-ROM that contains data file; however, audio recording is not supported at this time. Writing to CD-RW disks, which are rewritable, is also not supported at this time.

The first step is to create a logical disk and container file on your hard drive. Organize the directory structure, volume information, and files on the logical disk as you want them to appear on the CD-ROM.

The second step is to run CDRECORD.COM to transfer the contents of the container file to a blank CD-R disk. CDRECORD.COM provides a set of commands you can use to:

• Display information about the CD-R drive



• Set up the logical disk and container file



• Write to a CD-R disk



• Reuse an existing container file



• View online help

To view online help about CDRECORD.COM, enter the HELP command at the DCL prompt ($), as follows:

$ @SYS$MANAGER:CDRECORD H

Preparation  

When you are ready to create a CD-ROM, make sure you have:

• A CD-R or CD-RW drive connected to a system running OpenVMS Alpha Version 7.3-1 or later and I64.



• A blank CD-R disk.



• The device name of the CD-R drive (DQnn). If you do not know the device name, use the SHOW DEVICE DQ command. The device name for a CD-R drive is typically DQA0, DQA1, DQB0, or DQB1.



• The DIAG, PHY_IO, and SYSPRV privileges. If you want to run at a higher priority level, you need the ALTPRI privilege as well.

To verify that you have the device name for the drive, enter the INQUIRE command followed by the device name. For example:

$ @SYS$MANAGER:CDRECORD INQUIRE DQA1:

Setting Up a Logical Disk and Container File  

You set up the structure and data you want on the hard drive, then use CDRECORD.COM to transfer everything to a blank CD-R disk. You do this by first creating a logical disk on the hard drive that you can mount, dismount, and generally treat as an actual disk. You also create a container file because CDRECORD.COM needs to work with the files on the logical disk as a single entity.

For best performance, clean up and defragment the hard drive on which you will create the logical disk and container file. For more information, see BACKUP/IMAGE in the HP OpenVMS System Management Utilities Reference Manual: A--L.

Use the SETUP command in the following format to create a logical disk and a container file:

@SYS$MANAGER:CDRECORD SETUP filename LDAn: label nnnn

filename is the name of the container file. Follow the usual rules for naming files and include a file extension.

LDAn: is the name of the logical disk and can have a value of LDA1 to LDA9999.

label is the volume label you want to give the logical disk and the CD-ROM you will write. Follow the usual rules for assigning volume labels.

nnnn is the number of 512-byte blocks you want to allocate for the container file. The number must be a multiple of 4. The default value is 1250000 (640 MB).

The container file must not be larger than the available space on the CD-R disk you are going to write to. Also, check the available space on your hard drive to make sure you have enough room for the container file.

In the following example:

$  @SYS$MANAGER:CDRECORD SETUP TESTFILE.DSK LDA1: FRED 1250000

LDA1: is the device name of the logical disk.

FRED is the volume label of the logical disk and the CD-ROM you will write.

1250000 is the space (in 512-byte units) that will be allocated on the hard drive for the container file.

Once you have created a logical disk and container file on your hard drive, you can populate the logical disk with directories and files.

Populating the Logical Disk  

Mount the logical disk and use OpenVMS commands such as CREATE/DIR, COPY, etc., or Record Management Services (RMS), to create files on the logical disk. You can dismount and remount the logical disk any number of times and update its contents as often as necessary. You can also apply UIC-based security and access control lists (ACLs) to files.

Once you are satisfied with the contents of the logical disk, you are ready to write it to a CD-R disk.

Writing to a CD-R Disk  

When you are ready to write to a CD-R disk, do the following:

1. Turn off other applications to ensure that the write operation will not be interrupted. An interruption might result in unreadable space on the CD-R disk. The write operation must complete to create a readable CD-ROM. You cannot reclaim the space used by an unfinished write operation.
2. Enter the WRITE command in the following format:@SYS$MANAGER:CDRECORD WRITE filename LDAn: DAQnn: laser speed prioritywhere:
   
   filename is the file name and file extension of the container file.
   
   LDAn: is the name of the logical disk and can have a value of LDA1 to LDA9999.
   
   DQnn: is the device name of the CD-R or CD-RW drive.
   
   laser turns the laser beam on or off and can have a value of 0 (enable) or 1 (disable). The default is 0. Set this parameter to 1 (disable) when you want to test the process before actually writing to a CD-R disk.
   
   speed is the recording speed for the write operation and can have a value from 0 to 99. The default value is 0. CDRECORD.COM automatically determines the maximum recording speed based on the speed of the drive and the media speed rating. When speed is set to 0 (the default), CDRECORD.COM uses the maximum recording speed it automatically calculates. You can override this recording speed by entering a number from 1 to 99.

   ---

   A CD-R or CD-RW drive might write at one of a number of fixed speeds (for example, at 2x, 4x, 8x, 16x, and 20x). Enter an override speed to set the drive to one of the speeds that it is capable of using. If you enter an unsupported speed for the drive, CDRECORD.COM picks a supported speed close to what you specified.

   ---

   priority lets you increase the base priority for the current process. Increase the priority to avoid buffer underruns that could cause a failure in the write operation. You can specify a priority between 1 and 63. If you do not specify priority, your base priority is retained. If you increase the base priority, after the write operation completes you are asked if you want to reset the priority to its original level. If you answer no, the increased priority level is retained.

You should know whether or not your drive is required to record at a specific speed. With some drives, to minimize errors, you might need to record at a slower speed, depending on the ability of your computer to keep up the pace. You do not want the write operation to pause because the computer cannot provide the data quickly enough. Some drives can accommodate sporadic recording activity ("burn-proof" drives). Raising the priority parameter can also alleviate problems.

In the following example:

$  @SYS$MANAGER:CDRECORD WRITE  TESTFILE.DSK LDA1: DQA0: 0 12

LDA1: is the device name of the logical disk.

DQA0: is the device name of the CD-R drive.

0 enables the laser beam.

12 is the recording speed.

Verifying a Write Operation 

After you create CD media, you can verify that the data written to a CD-ROM can be read back and that it matches the original data. To verify data, enter the VERIFY command, using following format:@SYS$MANAGER:CDRECORD VERIFY filename LDA1: label DQA0:

where:

filename is the name of the container file and its extension.

LDA1: is the device name of the logical disk.

label is the volume label of the logical disk (and the CD-R media).

DQA0: is the OpenVMS CD device name.

Reusing a Container File  

When you have finished writing the contents of a logical disk to one or more CD-ROMs, you can delete the container file or reuse it, if you plan to create more CD-ROMs in the future. The advantages of reusing it are:

• The space on the hard drive is already allocated. It is better to keep it intact, especially if space is an issue.



• It saves steps.

Reusing a container file DELETES the current contents of the file.

@SYS$MANAGER:CDRECORD REUSE filename LDAn: label

filename is the name of the container file and its extension.

LDAn: is the device name of the logical disk.

label is the volume label of the logical disk.

In the following example:

$ @SYS$MANAGER:CDRECORD REUSE TESTFILE.DSK LDA1: FRED

LDA1: is the device name of the logical disk.

FRED is the volume label of the logical disk.

Use OpenVMS commands to create directories and files. Once you are satisfied with the contents, you are ready to write to a CD-R disk with the CDRECORD WRITE command.

CDRECORD Command Summary  

The format for the CDRECORD.COM command line is:@ SYS$MANAGER:CDRECORD command [parameter1|parameter2|...]

The CDRECORD commands are:

• HELP
  
  Displays online help.



• INQUIRE
  
  Displays information about the CD-R or CD-RW drive.



• REUSE
  
  Lets you repopulate an existing logical disk and container file.



• SETUP
  
  Establishes a logical disk and container file on the hard drive.



• VERIFY
  
  Lets you check the results of a WRITE operation.



• WRITE
  
  Records the contents of a logical disk to a CD-R disk.

CDRECORD.COM Commands and Parameters summarizes the parameters for each command.

Table 12   CDRECORD.COM Commands and Parameters

HELP COMMAND	[OVERVIEW|INQUIRE|SETUP|REUSE|VERIFY|WRITE]
OVERVIEW	Displays online help on using CDRECORD.COM to create a CD-ROM.
INQUIRE	Displays online help for the INQUIRE command.
SETUP	Displays online help for the SETUP command.
REUSE	Displays online help for the REUSE command.
VERIFY	Displays online help for the VERIFY command.
WRITE	Displays online help for the WRITE command.
INQUIRE	DQnn:
DQnn:	Device name of the CD-R or CD-RW drive. The first two characters must be DQ. The third character is an alphabetic character from A to Z. The fourth character must be 0 or 1. The default is DQA0.
REUSE	filename LDAn: label
filename	File name and extension of the container file.
LDAn:	Name of the logical disk. Can have a value of LDA1 to LDA9999. The default is LDA1.
label	Volume label of the logical disk.
VERIFY	filename LDAn: label DQnn:
filename	File name and extension of the container file.
LDAn:	Name of the logical disk. Can have a value of LDA1 to LDA9999. The default is LDA1.
label	Volume label for the logical disk and the CD-ROM. Follow the usual rules for assigning volume labels.
DQnn:	Device name of the CD-R drive. The first two characters must be DQ. The third character is an alphabetic character from A to Z. The fourth character must be 0 or 1. The default is DQA0.
SETUP	filename LDAn: label nnnn
filename	Name of the container file. Follow the usual rules for naming files and include a file extension.
LDAn:	Name of the logical disk. Can have a value of LDA1 to LDA9999. The default is LDA1.
label	Volume label for the logical disk and the CD-ROM. Follow the usual rules for assigning volume labels.
nnnn	Number of 512-byte blocks to allocate for the container file. The number must be a multiple of 4. The default value is 1250000 (640 MB).
WRITE	filename LDAn: DQnn: laser speed priority
filename	File name and extension of the container file.
LDAn:	Name of the logical disk. Can have a value of LDA1 to LDA9999. The default is LDA1.
DQnn:	Device name of the CD-R or CD-RW drive. The first two characters must be DQ. The third character is an alphabetic character from A to Z. The fourth character must be 0 or 1. The default is DQA0.
laser	Turns the laser beam on or off. Can have a value of 0 (enable) or 1 (disable). The default is 0.
speed	Recording speed for the write operation. Can have a value from 0 to 99. The default value is 0 to accept the maximum recording speed calculated by CDRECORD.COM. A value of 1 to 99 manually sets the recording speed (to that value).
priority	Changes the base priority for the current process. Can have a value of 1 to 63. If you do not specify a value, your base priority is retained. If you change the base priority, you are asked if you want to reset the priority to its original level. If you answer no, the increased priority level is retained. Requires ALTPRI privilege.

The steps for creating a CD-ROM are:

1. Use the INQUIRE command to verify the device name of the CD-R drive. For example:

   $  @SYS$MANAGER:CDRECORD INQUIRE DQA0:

2. Use the SETUP command to set up a logical disk and container file on the hard drive. For example:

   $  @SYS$MANAGER:CDRECORD SETUP TESTFILE.DSK LDA1: FRED 1250000

3. Populate the logical disk by using OpenVMS commands such as CREATE/DIR and COPY.
4. Use the WRITE command to write the contents of the logical disk to a CD-R disk. For example:

   $  @SYS$MANAGER:CDRECORD WRITE TESTFILE.DSK LDA1: DQA0:

1	The CDRECORD software internals were developed outside HP and are protected by the GNU General Public License Version 2. Copies of the sources and the GNU license are on the Open Source Tools CD, which ships with each version of OpenVMS and is also on the OpenVMS web site.

( Number takes you back )

Copying and Transferring Files

Understanding Hard Links