topic Re: 4Node P4500 constantly restriping in StoreVirtual Storage

4Node P4500 constantly restriping

MattGG — Tue, 31 Mar 2015 03:47:58 GMT

I have a 4 node P4500 (10.00) with 12 NR5 LUNs and 68% capacity remaining.

The LUNs are constantly restriping. It is usually 2 at a time.

What would cause this? Where can I look to troubleshoot this issue.

Thanksm

-MattGG

P.S. This thread has been moved from Storage Area Networks (SAN) (Enterprise) to HP StoreVirtual Storage / LeftHand. - HP Forum Moderator

Re: 4Node P4500 constantly restriping

a_o — Thu, 12 Mar 2015 22:33:33 GMT

Basically, for an existing LUN, re-striping occurs when a node goes down for a while and then comes back up.

If it's been down for a while, re-striping will take longer so that the down nodes are 'caught-up'.

Otherwise, re-striping can occur when you've made changes to your LUNs -i.e. NR10 ->NR5, etc

There's no log per-se in SAN i/Q to view that would let you know why the node went down after the fact.

However, in CMC go to one of the nodes, expand to "Diagnostics->Log Files", RMC and save the "eventMan.log". Open in Notepad, search inside the file for "Event Manager Startup" and make note of the time stamp. This indicates a re-boot.

Also, search for "resyncSaniqObjects", and look for your LUN names in the vicinity.

This will let you know when your re-stripes started.

However, it would help if you give more information about your set-up:

Are they in the same site in a multi-site cluster?

Do they ever complete the re-stripe?

Re: 4Node P4500 constantly restriping

MattGG — Fri, 13 Mar 2015 02:24:51 GMT

They are in the same site.

It seems like there are always 2 restripes going on. They complete and 2 different LUNs begin to restripe. The network RAID level has not changed and no new LUNs have been added in at least a month.

Thanks,

-MattGG

Re: 4Node P4500 constantly restriping

a_o — Fri, 13 Mar 2015 12:36:21 GMT

It would seem that one or more of your nodes has been going down or disconnected without being noticed.

It coould also be a networking issue with the downed nodes.

Again, if the re-stripes are running for long enough that you're noticing them, the main contributing factor would be loss of a node. Also, note that if the LUNs are large in size you will tend to notice them re-striping, even if the downed node was down for a few seconds.

If you can't find any clues in the above mentioned logs, I would give support a call.