Performance › Exploitation of the zIIP Specialty Processor

Exploitation of the zIIP Specialty Processor

CA Vtape is designed to exploit IBM zIIP specialty processors when they are installed and enabled on the system where CA Vtape is active and the parmlib attributes are configured correctly. By default, CA Vtape will not attempt to make work eligible to run on the zIIP. You must activate zIIP processing using the zIIPExploitation= and PercentRunOnZIIP= attributes in parmlib.

The Virtual Device Engine for CA Vtape is designed to run in Service Request Block (SRB) mode, a prerequisite of zIIP processing. When the zIIP feature is activated, CA Vtape will create the environment necessary to schedule work on the zIIP. All Virtual Device Engine processing, including compression and decompression processing, runs in SRB mode; therefore the most processor intensive functions of CA Vtape can be made eligible to run on the zIIP.

When the zIIP feature is activated, CA Vtape creates the environment necessary to enable all or a percentage of its Virtual Device Engine work for zIIP processing.

For example, when you specify zIIPExploitation=Y to active zIIP support and PercentRunOnZIIP=20, every fifth Virtual Device Engine SRB will be enabled for zIIP processing.

Note: IBM documents that work enabled to run on a zIIP processor may not be processed on the zIIP for a number of reasons. Refer to the appropriate IBM documentation for further information on the zIIP.