The Backstore Engine › Overriding and Resetting Subgroup Automation

Overriding and Resetting Subgroup Automation

When required, you can override Subgroup Automation by using the SVTn SET BACKstore=-Release | -Hold,Group=nn console commands. The minus sign turns automation off for the subgroups targeted by the command and then releases or holds all manual subgroups targeted by the command.

For example, if SVTn SET BACK=-R,G=31 is issued and subgroups Short and Medium for group 31 are automated, the command would turn off automation for Short and Medium and then release Short, Medium, and Long. The command first made Short and Medium manual groups by turning off their automation and then released all the manual subgroups for group 31 which included Long.

After being deactivated, you can restore Subgroup Automation by issuing the SVTn SET BACKstore=reseT,Group=nn console command. The command will access the parmlib to determine the defined settings for the subgroups targeted by the command and return the affected subgroups to these settings. This may or may not cause the status of the subgroup queues to change.

The status of an Externalization Subgroup Queue is changed by Subgroup Automation when the Cache In-Use percentage is equal to or greater than the CacheAutoReleaseHighThreshold or equal to or less than the CacheAutoHoldLowThreshold. If Subgroup Automation is reset when the Cache In-Use percentage is between the CacheAutoReleaseHighThreshold and the CacheAutoHoldLowThreshold, the status of the Externalization Subgroup Queues will not be changed. The queues are left in whatever status the last override command put them.

For example, CacheAutoReleaseHighThreshold is set to 50%, CacheAutoHoldLowThreshold is set to 20%, and the status of all the automated Externalization Subgroup Queues is HOLD when the SVTn Display Group console command is issued. This is their status because Cache In-Use has not exceeded the release setting. The SVTn SET BACKstore=-Release,Group=* console command is issued to override Subgroup Automation and release all the now manual Externalization Subgroup Queues. Externalization lowers the Cache In-Use percentage to 30% and the SVTn SET BACKstore=reseT,Group=* console command is issued to reactivate Subgroup Automation. The Externalization Subgroup Queues will remain in RLSE or ACT(n) status when the SVTn Display Group console command is issued. The queues will not be reset to HOLD status because the Cache In-Use percentage is not equal to or less than the CacheAutoHoldLowThreshold value.

In this situation, if the status of the queues should be HOLD, issue the SVTn SET BACKstore=Hold,Group=* console command to return the automated queues to manual control and hold them. Then issue the RESET console command to restore Subgroup Automation.

If overriding and resetting Subgroup Automation becomes a regular event that must be automated, then you should set the queues to the desired status before the RESET. For example, an hour before the off-site movement of physical tapes, the queues may be released to copy as many Virtual Volumes to physical tape as possible. The commands to automate and the order to automate them would be as follows:

1. SVTn SET BACK=-R,G=*, to first deactivate Subgroup Automation and release the now manual queues.
2. SVTn SET BACK=H,G=*, to return the queues to HOLD status.
3. SVTn SET BACK=EXCLVOL,G=*,T=D, to release the DUPLEX physical tapes for off-site movement.
4. Create the off-site movement pull list.
5. SVTn SET BACK=T,G=*, to restore Subgroup Automation.

Note: For more information about the syntax and options of these commands, see the chapter “Console Commands” in the Administration Guide.