Reallocate schedule

[igor]

Hello 2 all!

I've set up reallocation jobs to run against a test LUN, by  settings the threshold limit to 4 and establishing a twice-a-week schedule -  at 11PM on Sundays and Wednesdays:

          reallocate start -t 4 -p /vol/TEST/test.lun
          reallocate schedule -s "0 23 * 3,0" /vol/TEST/test.lun

I  had expected the reallocation (optimization) process to commence  automatically once the threshold is reached, but it doesn't.

I only keep  getting system messages in my Autosupport, advising me to run  reallocate:

Wed Dec 29 23:00:00 CET [wafl.scan.start:info]: Starting WAFL layout measurement on volume TEST.
Wed Dec 29 23:10:19 CET [wafl.reallocate.check.highAdvise:info]: Allocation check on '/vol/TEST/test.lun' is 4, hotspot 19 (threshold 4), consider running reallocate.

Sun Jan  2 23:00:00 CET [wafl.scan.start:info]: Starting WAFL layout measurement on volume TEST.
Sun Jan  2 23:10:16 CET [wafl.reallocate.check.highAdvise:info]: Allocation check on '/vol/TEST/test.lun' is 5, hotspot 19 (threshold 4), consider running reallocate.

Surely this should've been done automatically by now?

Cheers,

Igor

[chriszurich]

I'm guessing this may be a case where the threshold specified (4) must exceed the current threshold of the volume being queried.  In your case it sounds like the volume has a current optimization level of 4 which matches/equals your optimization threshold.  To test this theory set the reallocate threshold to 3 and see if the reallocate job runs against the volume.  If it does then this would indicate that my theory is correct.

You could also add the -n option to have it skip checking the threshold or simply remove the -t option.

[igor]

I thought so too... But as you can see In the second line, the threshold has already been exceeded (5) and still nothing happened.

Thanks for the alternatives provided Chris, however I would still like to utilize threshold limits since it's an entrey level system with other workloads going on around the clock. I would like to avoid increasing CPU load and disk utilization unnecessarily. (wouldn't we all?:)  I only wish someone could tell me what went wrong.

[chriszurich]

Woops, looks like I didn't catch that second line.  Yeah, you definitely have a valid point.  Just out of curiosity what version of Data ONTAP are you running including release pack?

[igor]

DOT 7.3.4.

P.S. Is there a TR document for reallocation available? There's nothing on NOW.

[radek_kubka]

Yeah, awesome question - the answer is still "no" from what I know

Have you seen this thread though?

http://communities.netapp.com/message/20969#20969

Regards,
Radek

[igor]

Yes. Intense discussion about many reallocation aspects.   Threw in my question as well, but no reply. Pitty.

[merick]

Hello, I know this is an old thread, but is it possible there was a measurement scan done on the volume initially? I have a feeling the scheduled reallocation is doing a "measure only" scan.

"reallocate status -v" will show the flags for the reallocation. If you see something like this:

Flags: whole_vol,measure_only,repeat,keep_vvbn

That indicates it will only do a measurement regardless of the threshold set. The output should look like this:

Flags: whole_vol,maybe_realloc,repeat

Thanks,

Erick

[tutututu01]

Hi All,

no answer for this?

No documented procedure for a secure way of 'measure' and 'start' ?

Regards,

Gwenael

[cfizz34]

If I am seeing this 'Flags: measure_only,repeat' <What did I do wrong when I set up my schedule and how can I correct it?