High CPU Consumption Tape IO and KSleep System Calls

[Bill Slaughter]

I have an application (Tivoli Storage Manager - a.k.a. TSM) that is a multi-threaded application. We have recently upgraded our server software (to 5.1.7.2). The software requires a new device driver that does the tape/library IO.

I am noticing that each Tape IO Thread is consuming (at times) 90-100% CPU. Well beyond what the old release would do.

We did some searches on the ITRC and found some possible matches where PHKL_23955 talks about the "Performance Boost" enhancements that were subsequently regressed. These also had numerous KSleep system calls in them.

We applied the fix PHKL_28314 and all of its pre-reqs and it seemed to resolve the problem. We declared victory on the test system and moved on to updating production.

Yesterday I discovered high CPU usage on the production system (DeJa Vu). I double checked and the problem does still exist on the test system.

I double checked the patches/upgrades have been applied to the test system and don't see anything that could have caused us to regress the problem.

Has anybody else seen any High CPU behavior like this?

We have placed support calls for both Tivoli and HP and are awaiting callbacks/resolution from both.

Bill

[Steven E. Protter]

swverify \*

Look for errors.

If need be:
swconfig \*

Beyond that, all I can say is you seem to have taken all the right steps.

You should have March or June 2003 patches installed, and might want to browse patches that deal with I/O issues.

SEP