F backing up and restoring the system disk, F.1 reasons for backing up the system disk, F.2 suggested procedures – HP BA322 90087 User Manual
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F Backing Up and Restoring the System Disk
This appendix describes how to perform backup and restore operations on the system disk. You
perform these tasks by entering commands from a specialized backup environment. You access
this environment through the menu that is displayed when you boot the OpenVMS Alpha CD
or the OpenVMS Integrity servers OE DVD, or through an alternative method that does not
require the CD or DVD.
This specialized backup environment is required because it allows you to create an exact copy
of the system disk. You cannot create an exact copy in a standard operating system environment
because the OpenVMS Backup utility saves only what is on the disk at the moment the BACKUP
command is executing, excluding portions of open files contained in memory or data about files
not yet written back to the disk (cache).
For more information about backup operations, including procedures for backing up and restoring
files and directories, see the HP OpenVMS System Manager's Manual, Volume 1: Essentials.
F.1 Reasons for Backing Up the System Disk
The primary reason for having a backup copy of the system disk is so you can fully restore your
system in case any hardware or software problem affects the integrity of your original system
disk or your ability to access it. For example, use the backup copy to restore your system under
the following conditions:
•
When a problem occurs during an OpenVMS upgrade or update, or during the installation
of other software products. If you back up the system disk before you attempt any of those
procedures, you can restore the system disk and attempt the procedure again.
•
When a system file that is accidentally deleted renders the system disk nonoperational. If
you back up the system disk after you installed or upgraded the OpenVMS operating system
and any other software products, you can restore the system disk.
•
When the drive that holds the system disk malfunctions. If you have a backup copy of the
system disk, you can restore it to a functioning disk and continue to use the system.
Another reason for backing up the system disk is to eliminate disk fragmentation, which occurs
when files are stored noncontiguously on the disk. The BACKUP/IMAGE command creates a
copy on which files are stored contiguously.
F.2 Suggested Procedures
HP recommends the following:
•
The preferred method for performing system disk backup and restore operations is to boot
the operating system media, choose the DCL option from menu, and then enter the
appropriate backup commands. The detailed procedures are described in
and
However, if you do not have access to the CD or if you want to back up a shadowed system
disk without disabling the shadow set, you can use a different procedure, which is described
in
.
•
Store the backup media in a safe place.
•
If you have an OpenVMS Cluster environment with more than one system disk, be sure the
volume labels on each system disk and on backup copies of system disks are unique. Use
the SET VOLUME/LABEL command to change a volume label, if necessary.
F.3 OpenVMS Cluster Caution
If any nodes except the node used to run BACKUP are booted during the backup operations
described in this appendix, your cluster will become partitioned, where nodes in the existing
cluster divide into two or more independent clusters. This condition can cause data file corruption.
In addition, these backup environments do not restrict your use of DCL commands to the BACKUP
command only, which further increases your risk of accidentally destroying or corrupting data
F.1 Reasons for Backing Up the System Disk
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