StorageTek 6 manual Redistribute Scratch Volumes in the Library, Define CAP Preferences

Redistribute Scratch Volumes in the Library

The Scratch Redistribution utility allows you to redistribute scratch volumes across the LSMs within a particular ACS. You can choose to have the scratch volumes go to only specified LSMs or all LSMs within an ACS.

Redistribution is performed to an evenness defined by the balance tolerance level which is specified via the Scratch Redistribution utility. If necessary, the Scratch Redistribution utility swaps scratch volumes with nonscratch volumes to equalize the count of scratch cartridges in an ACS.

Refer to Chapter 4, “Utility Functions” on page 169 for detailed information on the Scratch Redistribution utility, syntax, and parameters.

Maintain Quantities of Scratch Cartridges

Typically, in a high-activity environment, if there are insufficient quantities of scratch volumes available within a library, production time can be lost. Scratch volumes are maintained in scratch pools that are defined across the library LSMs. It is important that the number of cartridges maintained in the scratch pools are sufficient enough for normal library operation at your data center. The operator or the systems programmer can control when the HSC warns of low quantities of scratch cartridges.

The Warn command establishes thresholds which control when the HSC notifies the operator of an insufficient quantity of scratch cartridges in an ACS. The scratch pool depletion warning notifies the operator when the number of scratch volumes in an ACS falls below a specified minimum value.

By specifying warning thresholds, you can know when the number of scratch cartridges is too low for normal library operation.

Refer to the HSC Operator’s Guide for more information about the command, syntax, and parameters.

Define CAP Preferences

The physical configuration of your library, especially the location of CAPs, can affect both library performance and operator performance. For a more efficient operation, ideally the operator should be located close to the CAPs being used the most. You can control which CAPs are most used.

The CAP preference (CAPPref) command enables you to specify preference values for CAPs. If CAP preferences are not specified, the CAP preference value is set to zero. A CAP with a preference value of zero is never selected (defaulted to) by the HSC unless specifically requested. The CAP preference list specified in the command establishes an ordered list of CAPs for use during cartridge entry and ejection. The HSC chooses an available CAP from this list by starting at the highest priority and moving down the list until a nonbusy, nonzero-priority CAP is identified.

414VM/HSC 6.0 System Programmer’s Guide

1st ed., 6/30/04 - 312579601