What you observe is expected at this level of code. Additional tasks are now counted which can account for a 10-20% increase in reported DA CPU busy. Disk response times should not have degraded as a result (maybe even improved) of this upgrade. Also at this code version, the FAST relocation rate may be a little more aggressive, contributing to DA busy. You could try changing your FRR value if you are actually seeing performance degradation as a result of the code upgrade.

Thanks Jason that's what I wanted to confirm.  I wish they would list things like this in the release notes.

Yes, this change should have been in the release notes.

There is a fix coming in the next SR which will remove some operations from the DA % busy and move those to the LP % busy. 

The fix that increased the DA busy in some cases was 66045, and was introduced in Arno.  It wasn't written up in the release notes, but should have been.  For many workloads it made the DA % busy more accurate.   In some cases it also counted some background iVTOC and WP scan activity in the % busy.

There is a fix (67571) that is in the Q3SR that will move that iVTOC scan and some of the WP scan activity to the % LP busy. 

Thanks for all the info Quincy!

Quincy - Are these release notes you are referring to available on the support site or are the release notes only available to EMC employees?  The notes on the support site that I saw didn't seem to point any of this out.

Also any details of the fix you are referring to would be great.  Definitely seems to be a fix that we would benefit from.