Hi guys,
I am seeing increased cpu on a filer. It appears to jump when the filer kicks off a number of snapmirrors. I've updated the threshold so that the mirroring runs a little more frequent and this appears to have reduced the high cpu issue. Note, I'm only running approximately 4 snap mirror threads on a clustered environment so I'm not hitting any mirroring thread limitations.
This increase in cpu is unexpected as the filer is running around 50% less snapmirror threads and 40% less volumes from 6 months ago. so if anything I should see a drop in cpu activity.
Support are advising me to run a 'wafl scan reallocate' as one volume is close to 80% full. I'm not convinced and reluctant to kick off wafl commands.
For your information, I'm running 6.5.3P4 on a 940C cluster.
Has anyone else had similar issues or have ran 'wafl scan reallocate'. Any recommendations for debugging?
I've passed on the relevant 'sysstat' data for a 24hr period to Netapp Support.
Regards, Philip