Load balance in EVA 5000

[RogerVI]

I have the following situation:

I have an EVA 5000 in a SAN configuration which is managed by the Command View EVA Software (version 6.0.2.37). This array have two controllers (A and B, both of them running the HSV SR0025vcsp-3110 software )

I realized that almost all virtual disks created in the array are managed by the controller B.

When I create a new virtual disk using the Command View EVA, I see (in the tab Presentation) that the Managing controller is the Controller B. I've probed several times with several virtuals disks and the situation is similar.

There are occasions when the users indicate some performance problems when they run the databases applications.

I run the EvaPerf software and I see that the controller B have a heavy workload compared to controller A.

Why the Controller B is the Managing controller for almost all virtual disks ?

Can I change this behavior ? Or it is by configuration ?

Thanks in avance

[IBaltay]

hi,
you can change it on EVA during the presentation of the disk by choosing the set preferred path controller a failover/failback and set preferred path controller b failover/failback option. You can redo all vdisks in this manner to distribute them evenly across both controllers (you should stop the host io for a short time for that.

[Amar_Joshi]

I will suggest you to look into host configuration too. It may so happen that your host multipathing software is not configured to use both the paths. In case of HPUX native volume manager, if the volumes are created in such that the primary volume always comes from one controller then even though you set preferred-path settings on EVA it will bring them over to the controller where most IO requests are coming. It is a build in feature to EVA which overrides manual preferred path settings.

In case of Windows you should be setting the SQST (Shortest Service Queue Time) to optimize the path/controller utilization.

Also please check and compare two SAN switches if one of them is causing this issue.

[RogerVI]

Thanks for all