topic EVA8100 - Any impact while setting failback preference setting online. in Disk Enclosures

EVA8100 - Any impact while setting failback preference setting online.

junmeng — Mon, 22 Jun 2009 03:56:42 GMT

Hi,

Has anyone change their failback perference settings while applications are running online?

Any performance impact?

Thanks!

Re: EVA8100 - Any impact while setting failback preference setting online.

sreekanthtm — Mon, 22 Jun 2009 11:21:35 GMT

Hi,

Preferred path/mode -- Designate one controller, arbitrarily, as path A, and the other as path B. This setting provides a way of initially distributing the virtual disk load evenly between controllers. During operation, this path preference can be overridden later.

Failover only â Controller turns over control of all its virtual disks to the
other controller and remains inoperative.

Failover and failback â Controller turns over control of all its virtual disks to the other controller. If the condition that caused the failover no
longer exists, the controller automatically takes control of its own virtual disks again

You can change the preference online. And there won't be any performance impact if you are selecting "Failover and failback".

Rgds,
Sreekanth.

Re: EVA8100 - Any impact while setting failback preference setting online.

junmeng — Mon, 22 Jun 2009 13:38:22 GMT

Hi,

Assuming you change the failover setting for a particular vdisk to Path A Failover. (Assuming Controller B is the managing controller)

Will the setting take effect immediately when you click save in Command View EVA?

Re: EVA8100 - Any impact while setting failback preference setting online.

J Peak — Mon, 22 Jun 2009 14:06:34 GMT

The setting takes effect immediately.
We have done this on production volumes during the day.

During operation, the managing controller may change depending on your setting and circumstances. We have never had any impact by this change.

Re: EVA8100 - Any impact while setting failback preference setting online.

junmeng — Mon, 22 Jun 2009 14:14:46 GMT

Thanks for your help!

Re: EVA8100 - Any impact while setting failback preference setting online.

junmeng — Mon, 22 Jun 2009 14:15:20 GMT

Answer found!