aggr1/abc (9 disks, Disk Scrub: suspended, 47% complete) - what's this?

[rlk4508rlk]

aggr1/abc (9 disks, Disk Scrub: suspended, 47% complete) - what's this all about?  Is it a problem?  Should I resume the scrubbing?

I am thinking that scrubbing should be done, maybe monthly on weekends.  Does anyone have experience with this?  Is there a performance hit if done with production on a weekday?  Much of a hit?

[martin_fisher]

Hi

Disk scrubbing is performed automatically by ONTAP and normally occurs at once a week at 1am.. the process involves the filer scanning the media/disks for data errors. If errors are found, these are rebuilt from the parity and then the data should be re written to disk. Its a method of eliminating disk/data errors and keeps everything in order.

You can view the setting of the scrubs by entering the following CLI commands:

options raid.scrub.schedule 
options raid.scrub.enable off | on

The second option turns the scrub on or off. Performance hit, shouldnt be a problem unless lots of errors and reconstruction is required, but its also quite an important little feature.

Some more info here, but I couldnt find the later ONTAP manual at the time:

http://now.netapp.com/NOW/knowledge/docs/ontap/rel713/html/ontap/mgmtsag/4raid17.htm

Martin

[shane_bradley]

Its not a big deal, scrubs suspend if they dont complete before the morning (if i remember right) they'll just pickup again next weekend.

Do a "vol scrub status -v"

It will tell you when the last full scrub was completed.

vol scrub status -v
vol scrub: status of /aggr0/plex0/rg0 :
    Current scrub is 89% complete (suspended).
    Last full scrub completed: Sun Jan 23 01:39:05 NZDT 2011

vol scrub: status of /aggr0/plex0/rg1 :
    Current scrub is 89% complete (suspended).
    Last full scrub completed: Sun Jan 23 01:39:27 NZDT 2011

vol scrub: status of /aggr0/plex0/rg2 :
     Current scrub is 89% complete (suspended).
     Last full scrub completed: Sun Jan 23 01:39:49 NZDT 2011