HP 3000 Manuals HP 3000 Manuals
Restoring from Multiple Devices
To restore files from multiple devices, use the RESTORESET parameter in
the RESTORE command to reference the multiple devices. Use of the
RESTORESET parameter is explained in the following pages.
Sequential Devices
Sequential device configuration can be employed at times when you have a
large set of files to restore from a number of tapes and you want to
speed up the process. (The sequential device configuration is described
under "Using Devices Sequentially," in chapter 2.)
To restore files from sequential devices, do the following:
1. Mount the tapes on all of the devices you plan to use.
2. Use the FILE command to give each device a file name that
indicates its position.
3. Use the RESTORESET parameter in a RESTORE command to reference the
multiple devices.
For example, to restore files from three sequential devices, use the
following set of commands:
FILE SEQ1;DEV=7
FILE SEQ2;DEV=8
FILE SEQ3;DEV=9
RESTORE ;@.@.@;RESTORESET=(*SEQ1,*SEQ2,*SEQ3)
NOTE Do not backreference the file name of a backup device immediately
before the name(s) of the file(s) you are restoring when using the
RESTORESET parameter. Instead use a placeholder for the missing
parameter normally supplied when using a single backup device. The
placeholder is provided by the use of the first ";" in the RESTORE
command.
The above RESTORE command restores all system and user files from three
sequential devices. The parentheses surrounding backreferenced file
names group the devices into a device pool.
When RESTORE has transferred all the files from the first backup tape on
the first backup device, it immediately begins restoring files from the
second tape on the second backup device. While RESTORE continues, you
can unload the first tape and mount a new tape on the drive. When
RESTORE finishes restoring the files on the last device, it reverts to
restoring files from the first device. The process continues to cycle
through the devices in the device pool until it has restored all the
files you specified.
If you gave the backup devices a single file name such as
FILE T;DEV=TAPE
enter the following RESTORE command to restore files from a set of three
sequential backup devices:
RESTORE ;@.@.@;RESTORESET=(*T,*T,*T)
You can restore files that were created using parallel devices or
parallel device pools in a sequential configuration. For example, to
restore a set of reels that have been created using parallel device
pools, you must use the following logical order to mount the reels on
sequential devices: A1, A2....B1, B2 and so on. (The first alphabetic
character, in capital letters, indicates an original, unique parallel
set; the second numeric character indicates an original sequential reel
within the set.) That is, mount A1 first, followed by A2. The reel that
you mount prior to B1 should be the last "A" reel.
NOTE Sequential RESTORE is not available for labeled tapes.
Parallel Devices
A parallel device or parallel device pool configuration can be used for
restoring files. Therefore, you can use the same designations with the
RESTORESET parameter that you can use with the STORESET parameter.
(Refer to "Storing to Multiple Devices," in chapter 2.)
If you gave the backup devices a single file name such as
FILE T;DEV=TAPE
enter the following RESTORE command to copy files from a set of four
parallel backup devices:
RESTORE @.@.@;;RESTORESET=(*T),(*T),(*T),(*T)
Describe parallel devices in the RESTORESET parameter by enclosing each
backreferenced device file name within parentheses. Use commas to
separate devices.
To restore files from parallel device pools, use parentheses to group the
devices into pools. Separate the devices in the pool from one another
with commas. Commas also separate each device pool. For example, the
following commands copy files from two parallel device pools. Each
device pool contains two sequential devices. In the following example,
RESTORE uses a total of four devices divided into two device pools.
FILE PPA1;DEV=7
FILE PPA2;DEV=8
FILE PPB1;DEV=9
FILE PPB2;DEV=11
RESTORE @.OPERATOR.SYS;;RESTORESET=(*PPA1,*PPA2),(*PPB1,*PPB2)
If you gave the backup devices a single file name such as
FILE T;DEV=TAPE
enter the following RESTORE command to copy files from a set of parallel
device pools:
RESTORE @.@.@;;RESTORESET=(*T,*T),(*T,*T)
Notes Parallel RESTOREs can be performed only with tape sets that were
created with a parallel STORE option. A sequential RESTORE can be
used with any tape set.
Parallel RESTORE allocates every subset of the tape set (for
example, STORESET=(*T1),(*T2) creates two subsets) to distinct
parallel devices or device pools, and expects a volume belonging
to the subset to be mounted on its allocated device or device pool
only.
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