DL360 G5 running XenServer : Expand RAID5

[Thomas Lefebvre]

Hi everyone,

I'm getting in charge of some XenServers 5.6 running in production with critical VM's and a slightly too limited storage capcity; I'm therefore going to add one disk to the existing array but here comes the problem.

Isn't anyway to expand the RAID array while the server's running? I was hoping to at least see what controller is installed and it is setup remotely with the HP Array Configuration Utility but can only be used localy.

Am I litteraly obliged to reboot the Server, log into the RAID console check everything from the console while stopping my production VM's?

Thanks for your expertise.

[Michael A. McKenney]

I would not expand an active server. I would not reboot a server that is expanding a RAID partition until I was sure it was done. What size drives did you add? It could take 1-2 days depending on the size of the drives you are adding to RAID 5 and number of files. I hope you did a full verified backup before you expanded.

[Thomas Lefebvre]

I haven't done anything yet, I'm just figuring how to handle this thing.

As these are production servers, I "need" to expand the RAID while the VM's are running.

The RAID 5 is currently spanned over 3 x 72GB, I'm just adding one disk

[SMR]

To answer your question of whether there is a way to expand online, I'm afraid it's not possible. HP does not have an online version of ACU for XenServer.

To be on the safe side, make sure the server(s) have a battery backed cache module, once you confirm this, there sould be no risk in performing the array expansion. I'm assuming an snmp trap will be generated when the logical drive status changes from expanding to ok... that will keep you from rebooting just to check if it's finished, you won't be able to see the progress though.

Remember to set the proper "transform priority" on ACU while offline, if you set it low it may never finish since heavy disk activity will cancel the expand/extend operation.