The Rebalance script for IBM SVC has been updated

I found this in the Aussie Storage Blog

http://aussiestorageblog.wordpress.com/2013/04/22/ibm-scripting-tools-for-svc-and-storwize-has-been-updated/

 

Rebalancing of managed disk groups has to be done whenever you add new mdisks to a group - otherwise the IOPS and response
times on these managed disk groups become unbalanced and you will not see the expected performance out of the group.

 

More informations about unbalanced mdisk groups here

BVQ howto - Analyze MDisk Groups.pdf

 

Click on pictures to enlarge


in this picture you can see that most of the IO is handeled by only one managed disk.
It handles three times more IO than the other mdisks. This mdg will become a
performance problem soon when this one mdisk becomes more load and saturates.

 

This is how it is lookiong like in performance view. The green lines are IOPS from the
one mdisk and another with smaller load and thge red lines are the response times.
It is obvious that response time of the high load mdisk will become an issue soon.