I see on my NetApp (FAS 3220 with Ontap 8.2.3P6) a cpu of 288% on the service Exempt. Look at the NetApp page for what this service is but it only says: Exempt = General parallelized work
Now i see that at the same time arouind 16:00 the IOPS and latency is going up also. So my question is What does this Exempt service do? and as shown in the graphs after 40 min the service returnd to normal
There are a number of different processes that run in the exempt domain so it isn't really possible to unpick from these graphics.
I did, however, have a look at an AutoSupport for that system and it looks like one of the volumes has storage efficiency scheduled to run at 1500 on a daily basis. This lines up nicely with the spike in the chart.
If you don't see this spike every day then it may simply be because someone dumped a whole load of data into that volume and created a lot of work for the deduplication and compression engines.