Hi,
Its a very good observation. I am sure this is something, people will observe if they are on cDOT 8.3 onwards.
According to NetApp KBID:1001962
- Volumes that are polled for IOPS in CDOT versions 8.3 and above only show IOPS from the network blade (n-blade) or network IOPS of that cluster.
- Aggregates that are polled for IOPS in CDOT in general only show IOPS from the data blade (d-blade) or disk IOPS of that cluster.
Thus in any CDOT version of 8.3 and above, summing up the volume IOPS values will not equate to the aggregate IOPS values.
Note: In the past (all the way up to CDOT version 8.2), volume Polling for IOPS included the d-blade So at that time, summing up all of the IOPS for volumes contained on an aggregate would match that aggregate’s IOPS.
Hope this information helps.
THanks,
-Ashwin