Monitoring runaway jobs (was Re: Oh where has my disk space gone?)

[Martin Rowe <martin@xxxxxxxxxx>]

Hi all

One of the problems I've had in identifying what's eating up disk space
is where some job is quietly consuming temporary space which isn't that
easy to track down. Just this week our production machine seemed a little
slow, but nothing seemed to be using a big amount of CPU. One query job
occasionally hit around 15%, but that's not that unusual. I did notice
that overall disk space had gone up over 10% from the previous week (a
lot on a 300Gb box). As there didn't seem to be any other likely culprits
I took a closer look at the query, and saw that the temporary storage for
the job was over 26Gb! After ending the job, the disk space soon settled
down to its usual level.

That's happened a few times before, so I've now put together a routine
to check temporary storage use on all jobs in the system. That works
fine, but what it doesn't do is tell me about big files in QTEMP - which
I had *thought* would be part of a job's temporary storage.

I already have a nightly job that does a DSPFD *ALL/*ALL to an outfile
that I can run SQL over to see files by decending size, and have a stern
word with Query users who leave 1Gb files in their wake ;-) That takes
care of the permanent objects, but obviously a DSPFD isn't going to pick
up on QTEMP objects, so how would you track down where the space was
being consumed?

I can do this 'by hand' by looking at each likely job and taking option
13 (Display library list, if active) from a WRKJOB or DSPJOB, then option
5 against QTEMP to see the file sizes but I haven't seen a command or API
to duplicate this.

Ideally I'd like to have a background job fire up once every 15 minutes
or so and scan the system for potential disk hogs, and alert our Ops
department. Any ideas or suggestions welcome.

Regards, Martin
--
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