Changing managing controller on EVA 8100

[nodrog]

Hi, very little experience on EVA's but want to ask if there is any way through Command View or SSSU to change the managing controller of an presented LUN?  I believe this can be done with multipathing software in the OS but this is not an option to me. Thanks in advance.

P.S. This thread has been moved from General to Storage Area Networks (SAN) (Enterprise). - Hp Forum Moderator

[Hiren N Dave]

Go to EVA 8100 CV console and select virtual disk, select Presentation tab on right hand side window.

To change managing controller to Controller A, select Preferred path/mode to "Path A-Failover/failback" OR "Path A-Failover only"

To change managing controller to Controller B, select Preferred path/mode to "Path B-Failover/failback" OR "Path B-Failover only"

[Johan Guldmyr]

For SSSU:

http://bizsupport2.austin.hp.com/bc/docs/support/SupportManual/c02493404/c02493404.pdf

Manual to SSSU.

See page 80-81 and the command 'SET VDISK /vdisk/path PREFERRED_PATH='.

[nodrog]

Thank You for the replies and assistance. Is their any way that the managing controller can swap to the other without human intervention? Few months ago (June) the load was balanced between the two controllers i.e.. 50 percent of LUN presentations on controller A with Path A-Failover/Failback and the other 50 percent on controller B Path B-Failover/Failback. On a recent inspection (October) it was found that all the presentations for some reason has swapped to controller A with Path B-Failover/Failback. The EVA 8100 is on firmware ver. SR1142  6200.

[Johan Guldmyr]

"On a recent inspection (October) it was found that all the presentations for some reason has swapped to controller A with Path B-Failover/Failback. "

If it's set to Path B-Failover/Failback , doesn't that mean it's managed by controller B?

Yes, a LUN will be moved if more than 2/3 of the traffic are coming in through the proxy controller (the not-owner).

You need to set a preferred controller on the hosts as well.

[Rajiv]

There is also a possibility of LUNS moving to the other controller if there was a battery failure or the controller terminated for some reason. As per my knowledge Windows doesn't support failback so the LUN would need to moved to the other controller manually.

Thanks,

Rajiv

[Johan Guldmyr]

But this 'failback on a vdisk, wouldn't that would move the LUN back to the original controller after some kind of failure?

[Rajiv]

Failover & Failback are two different terms, Failover fails over LUN to other controller

The "failback"  works only on TRU64 and OVMS as per my knowledge since the Multipathing is built into these operating systems, for other Operating systems Multipathing is an external application. I may be wrong as well but what I am saying is from my experience. On Windows Failover works whereby if one controller fails the LUN is moved to the other controller.

Thanks,

Rajiv

[Johan Guldmyr]

http://technet.microsoft.com/en-us/library/cc725907.aspx

Where failback is listed in the DSM for Windows 2008.

Maybe it is possible in newer Windows?

[Rajiv]

Thanks for the link, the failback documented in MPIO is from host perspective not from the EVA controller perspective.  I don't think MPIO can force the failback of LUN from other controller to preferred controller unless there is an implicit transfer of LUN due to proxy IO.

Thanks,

Rajiv