Paging option of *FIXED vs *CALC

It has been some time since we have looked at this option so I decided to review this setting for storage pools. We have always found in the past that *FIXED performed better for us and that is how we have all pools set at the moment. I think the last time we evaluated this setting was back pm V5R4 and we are now at 7.1 (we skipped 6). We have 7 pools setup. Besides *MACHINE and *BASE we have *INTERACT , *SPOOL and three Shared Pools. *INTERACT is mostly traditional 5250 but also some jobs that we run all day doing interactive type transactions. One shared pool runs only ODBC/JDBC tasks from a system running on Linux but using DB2 as its database. Second shared pool is for QBATCH work. Third shared pool is for WTR jobs. *BASE runs everything else. (HTTP, Websphere, Zend, QCTL, QSERVER, QSYSWRK, QUSRWRK and a few 3rd party tools - Curbstone, Websmart, GoAnywhere.

We do not have any real performance issues with the exception of an occasional SQL requests coming on from the Linux systems via ODBC, where it will spike the CPU for a 4-5 seconds. And some outgoing JDBC requests from a job running on the i OS and getting data from a MS SQL system.

I have not seen many articles after 2010 on this setting and those I did find say to use *FIXED for 5250 work and *MACHINE and *CALC for anything doing only database (aka ODBC) tasks or do batch type work. "back in the day" IBM's recommendation was to try each setting and see which performed better and use that one. We found that *FIXED worked better for us.

QPFRADJ is setup to No Adjustment.

What do others run for these settings and for what type of workload?

Thanks


Mike Cunningham
VP of Information Technology Services/CIO
Pennsylvania College of Technology