2010-09-14 05:10 AM
I am looking at a filer with a lot of aggregates consisting of SATA. To make out what is what and reorganize some vols to higher performance aggregates I am trying to use the perf advisor to help me figure out which vols are using a lot of I/O.
I made some groupings of all the vols inside an aggregate and compared top objects -> vol IOPS to the IOPS generated by the underlying aggregate, suprise surprise: I have 3 aggregates consisting of 16 drives SATA each generating a consistent 1000-1200 IOPS with NO I/O showing for the volumes/LUNs inside each aggregate. No reallocates are running (also no measurements done), no snapmirrors on those aggrs. I cannot find out which process is generating those 1.000+ I/O per aggregate.
Solved! SEE THE SOLUTION
2010-09-14 11:00 AM
No Snapvault licenses, NDMP would actually be possible - will need to check on this. Sysstat -x shows me overall performance, with another 10 aggregates active on the system I see no way to isolate this to anything particular to my aggregate....
2010-09-14 11:03 PM
I have had this mystery in the past. In my case I had a lot of post snapshot house keeping jobs. You can view for a specific volume what is going on.
"priv set advanced; wafl scan status <volume name>"
On a completely idle volume you should only see a "active bitmap rearrangement" scan.
Snapshot related scans are:
snap create summary update
blocks used summary update
container block reclamation
And perhaps deduplication could be active.