Technical data

Using BACKUP
11.8 Using Disks and Tapes
How to Perform This Task
The two ways to initialize a disk during a backup operation are:
• When you perform an image copy to disk, BACKUP automatically initializes
the output disk, effectively erasing any existing files and volume-initialization
data on the disk. To preserve volume-initialization data on the output disk,
use the /NOINITIALIZE qualifier.
• When you create a sequential disk save set, BACKUP does not initialize the
output volume (by default). You can, however, instruct BACKUP to initialize
the output volume using the /INITIALIZE qualifier.
Examples
1. The following command shows how to initialize a disk on the BACKUP
command line:
$ BACKUP/IMAGE DUA1: DUA2:
This command initializes DUA2: using the volume-initialization data from
DUA1. BACKUP then copies the contents of DUA1: to DUA2:, effectively
erasing any existing files on DUA2. Note that the files on DUA2: are stored
contiguously, eliminating disk fragmentation.
2. The following command shows how to preserve volume-initialization data on
the output disk during an image copy:
$ BACKUP/IMAGE DUA1: DUA2:/NOINITIALIZE
This command causes BACKUP to initialize DUA2:, preserving the
initialization data on that volume. BACKUP then copies the contents of
DUA1: to DUA2:, effectively erasing any existing files on DUA2.
3. These commands cause BACKUP to initialize DJA2:, effectively erasing any
existing files:
$ MOUNT/FOREIGN DJA2:
%MOUNT-I-MOUNTED, USER1 mounted on _DJA2:
$ BACKUP/IMAGE DUA1: DJA2:DAILY.SAV/INITIALIZE
BACKUP then creates an image backup of DUA1: in the sequential disk
save set DUA2:[000000]DAILY.SAV. If the save set exceeds the available disk
space, BACKUP prompts for another volume. BACKUP initializes the new
volume and extends the save set in the master file directory ([000000]) of the
new volume. (For more information about save sets, see Section 11.5. For
more information about the /INITIALIZE qualifier, refer to the OpenVMS
System Management Utilities Reference Manual.)
11.8.2 Mounting a Volume
Mounting a volume makes it available to the system. BACKUP automatically
mounts tapes when you use them for a backup operation. Most disks on your
system are mounted at system startup. This section describes how to explicitly
mount volumes.
If you are planning to write a save set to a disk, decide whether the save set will
be written in standard Files–11 format or in sequential-disk format:
• If the save set will be written in standard Files–11 format, the target disk
must be mounted as a Files–11 disk.
11–16 Using BACKUP