topic Re: eva6100 controller resync in HPE EVA Storage

eva6100 controller resync

glennix — Fri, 09 Sep 2011 07:56:16 GMT

hi.

i'm running xcs 6220.

just want to ask if any of you guys have already experienced a controller resync w/ those hw specs. where there any downtimes experienced? i've read that a controller resync usually takes around 30 seconds. default disk timeout value for windows is 60 so i guess i don't have to tamper w/ that. any thing i should consider as well for an online resync if controllers?

thanks!

Re: eva6100 controller resync

Johan Guldmyr — Fri, 09 Sep 2011 09:43:44 GMT

Hi, a resync takes a minimum of 30s (without any disks installed) - it then increases with x seconds per TB of disk capacity that is installed.

See this post: http://h30499.www3.hp.com/t5/General/Re-sync-EVA5k-Controllers/m-p/5286457/message-uid/5286457/highlight/true#U5286457 for the EVA5000. I don't have the algorithm for your generation of the EVA in my head.

However, I found this advisory:

http://h20566.www2.hp.com/portal/site/hpsc/template.PAGE/public/kb/docDisplay/?javax.portlet.tpst=ba847bafb2a2d782fcbb0710b053ce01&javax.portlet.prp_ba847bafb2a2d782fcbb0710b053ce01=wsrp-navigationalState%3DdocId%25253Demr_na-c01974470

Which says "EVA storage systems with 21TB or more storage capacity may experience some host I/O timeouts when doing a dual controller resynchronization."

This translates to the same as what I wrote for the EVA5000 (about 1.43s per TB).

If you have over 21TB of installed disks it quite likely will take longer than 60 seconds.

Why do you need to do a resync? Often restarting the master controller solves the issue. But if you're doing an online firmware upgrade there's no way around it.

Re: eva6100 controller resync

Uwe Zessin — Fri, 09 Sep 2011 11:57:29 GMT

Hm, I thought restarting a single controller does an implicit resync, too.

What the field service people do is issue a special command that causes a parallel boot of both controllers without going through hardware diagnostics.

Re: eva6100 controller resync

Johan Guldmyr — Fri, 09 Sep 2011 12:11:27 GMT

A resynch restarts both controllers in parallell and a single controller restart only restarts one of the controllers.

I suppose when a single controller is restarted then there is some kind of resynchronization between the controllers to make sure they are in the same state, but only one controller restarts.

A resynch can be done manually via the 2a on /fieldservicepage but it can also occur if the array enters an abnormal state or the controllers are out of synch.

Re: eva6100 controller resync

glennix — Fri, 09 Sep 2011 14:17:15 GMT

my free disk space is being misreported so i'm thinking of a controller resync. So this probably means i have to do the resync offline- that is w/ the hosts and applications brought down - to avoid any errors/problems.

Re: eva6100 controller resync

Johan Guldmyr — Fri, 09 Sep 2011 14:57:57 GMT

I have many times seen the problem with the misreporting of free disk space being solved by rebooting only the master controller.
I definitely suggest attempting that before the resynch.
You find the master either by asking HP support or by looking in the menu in the front panel (OCP) of the HSV controller.

Re: eva6100 controller resync

glennix — Tue, 13 Sep 2011 08:48:18 GMT

Ok. Thanks. At least this will not entail any i/o disruption. generally speaking.