EVA6000 and controller load balancing question

[Tom Kunkel]

Hi fellow ITRC'ers

I have a question that I hope someone can answer better than google can. Basically, the situation is as follows: I have an EVA6000 and roughly 98% of all traffic is against one controller. All Vdisks are set to have no preferred path or mode, leaving the client OS to make that decision.
Now, because of IO issues, I need to forcefully rebalance and move several Vdisks to the idle controller. The host OS's are ESX3.5.4, Win2003R2 and HPUX11iv1/2.

Changing the controller and mode is disruptive to the host or will it not notice?

My users are p*ssed off enough as it is, so I really don't want to reboot servers if I can avoid it...

Any help, greatly appreciated.

[Bulent ILIMAN · Accepted solution]

EVA6K is an act/act array, so the transition will be transparent to your hosts. the point you shoul check is that your host shoul be accessible to both controllers of the EVA.

another point is that if you set back to no preference EVA can handle the balance back to the point where you started.

be sure you are on the latest XCS version, it can help about balancing also. latest must be 6.220

[Bhavnish Kamboj (BK)]

As above said the best option is to let the EVA decide about load balance. Select no preference for all the Vdisk and then both controller will take care of the I/O operations.

If you choose "No preference" option then Vdisk will move its ownership between both controllers automatically but hosts will not see any difference if they have access to EVA from both controllers.

BK

[Tom Kunkel]

Thanks all. Your feedback much appreciated. It was the confirmation I needed.