StorageTek Host Software Component 6.0, System Programmer'S Manual

Page: 314 / 718

284 VM/HSC 6.0 System Programmer’s Guide
1st ed., 6/30/04 - 312579601
Scratch Redistribution Utility
The Scratch Redistribution utility provides you with a way to balance the number of
scratch volumes across the ACS. It permits the redistribution of scratch volumes either:
• among LSMs implied by the specification of an ACS, or
• among the LSMs explicitly identified through an optional parameter.
This utility allows the user to select one media type and recording technique. If specified,
scratch volume redistribution will be based on the MEDia and RECtech settings.
Notes: If neither MEDia nor RECtech is specified, volumes are redistributed without
regard to media type or recording technique.
How the Scratch Redistribution Utility Functions
When only the ACS parameter is specified, the redistribution method transfers cartridges
from LSMs with a greater number of scratch volumes to LSMs with a lesser number of
scratch volumes. The process is repeated until the number of scratch volumes in each
LSM is within the defined scratch tolerance level.
Distribution in an ACS containing a mix of LSMs (4410s, 9310s, 9360s, 9740s) is
performed based on a percentage of scratch cartridges in the ACS. That is, the utility
causes each LSM to have the same percentage of scratch tapes within the ACS as the LSM
has cells within the ACS. For example, in an ACS where a 9310 LSM contains 80 percent
of the cells within the ACS, 80 percent of the scratch tapes will reside in the 9310.
Note: The SL8500 is a standalone library and cannot be combined with any
other LSM type.
After Scratch Redistribution is completed, only the specified LSMs contain scratch
cartridges, if the LSM parameter was specified.
Concurrent redistributions among different ACSs are accomplished by multiple
executions of this utility program.
Redistribution moves non-scratch cartridges to make space for scratch cartridges. The
actual number of scratch cartridges moved may vary depending on the number of free
cells and the number of scratch cartridges available.
Notes:
1. The Scratch Redistribution utility cannot be run concurrently with the Scratch
Update utility, or when the Audit utility is being run in the same ACS as the Scratch
Redistribution utility. An HSC message is generated, and the utility must be
resubmitted.
2. Cartridges cannot be transferred to a frozen panel.
Scratch Redistribution