HP Archive Backup System for OpenVMS Guide to Operations

3.1.5 Destination
3.1.6 Drives
3.1.6.1 Drive selection
Saving and Restoring Data
3.1 Archives
If you specify multiple consolidation criteria, ABS creates a new volume set when the first of
any of the defined criteria are exceeded. The default consolidation criteria is an INTERVAL of 7
days. If no consolidation criteria are specified, then ABS creates a new volume set when the
ANSI limits apply, or upon the first error writing to the volume set. This is not recommended as
you may create excessively large volume sets, and may have to split a volume set between onsite
and offsite (vault) locations. Consolidation criteria are only applicable to an archive type of
TAPE.
If you specified an archive type of DISK, you must enter a destination attribute for the archive,
or use the default of ABS$ROOT:[000000]. The destination contains the disk and directory location
of the data saved in this disk archive. When specifying destination, you should ensure that
the specified disk has enough free capacity to handle all data to be saved in this archive. ABS
does not monitor the disk for sufficient capacity. ABS clears this attribute if the archive type is
TAPE.
Also, if you have specified a logical name as part of the destination name, then ensure that before
the restore request is executed, the logical is defined as a concealed logical that is either defined
as a system-wide logical name or just has the physical device name before the restore request is
executed. If you do not want to use the logical name, then specify the physical device name followed
by the directory path as the destination for the restore request.
ABS allows you to enter a list of drives that can be used by save and restore operations to and
from this archive. This should be used only to restrict the drives that would normally be available
for these operations for some reason. Normally, you can let ABS select drives for all operations
based on media type and location, and so you do not need to specify the drives in the
archive. If you do specify drives, be aware that these drives apply to restores as well as saves.
Drives are only applicable to an archive type of TAPE.
When the drive list is specified in the archive class, the drive is allocated by ABS/MDMS for
operation as below:
1. Volume-set is not present in the archive class
ABS will allocate the first available drive and continues to select a volume matching the
selection criteria. If all the drives in drive list are not free then ABS will Indefinitely loop for
allocating the drives and wait for drive to be available.
2. When the volume set is present in the archive class and the required volume is present in:
– Slot - then ABS selects the first available drive from the drive list.
– Drive that is part of drive list in the archive class - In this condition the drive where the
volume is currently present will be used for save operation.
For example, if drive list consist of 2 drives A and B and if the required volume is present
in B, then drive B will be used for the save/restore operation even if drive A comes first in
the drive list.
3. Drive that is not a part of drive list - ABS will unload the volume from the drive and load the
volume in first available drive in the drive list.
Note
The above allocation algorithm is applicable only when drive list is specified in the
archive class.
Saving and Restoring Data 3–3