Seems like our Operations staff is always wanting to speed up the time it takes to shut an LPAR down and get it back up. But I've noticed that Db2 subsystems are taking longer to shut down, even with MODE(FORCE). Automation often is forced to MODIFY IRLM to get the subsystems down, which isn't ideal, since it leaves things in an inconsistent state.
We've automated console dumps for Db2 taking more than a couple minutes to come down, and sent them to IBM - in most cases, IBM tells us that Db2 is shutting down normally, but is taking a long time to do so. My understanding is that the time is typically spent in:
* Externalizing Db2 buffer data - with buffers in the GBs/10GBs, it's often a lot to write out.
* Closing datasets - this is the big one, we run a DSMAX of 170,000 on our Primary Prod subsystems, and on occasion we do get up there with actual open datasets.
Anyone else seen Db2 take longer to shut down, prior to routine maintenance or IPL?
Asking because...I'm wondering if it's worth opening an RFE to provide some mechanism for "pre-shutdown". I..e if it's late at night and you're getting ready to IPL, manually issue a command to the subsystem to start asynchronous tasks to do things like close datasets not actively in-use, or writing all BP/GBP changed pages to disk. Obviously not something you'd fire off during work because of the performance implications, but it might be useful to give Db2 a "head-start" on shutting down pre-IPL, so the time from STOP DB2 to SHUTDOWN COMPLETE is minimal, without actually stopping service.
Anyone else noticed an uptick in shutdown times for a Db2 subsystem?
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Mark Wieczorkowski
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Db2 Systems Programmer, SSA/DCS
Principal - Solipsistic, LLC
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