topic Re: Smart Array 641 & Mirroring in ProLiant Servers (ML,DL,SL)

Smart Array 641 & Mirroring

itadmin_2 — Wed, 30 Mar 2005 21:44:14 GMT

Hi people

I have an HP DL380G4 with a smart array 641 configured with 2 arrays.

Array #1 = 2xHDD's mirrored for SYS (nw65/sp2)
Array #2 = 4xHDD's Raid5 for VOL1 (incl 1 hot spare)

Is the following possible? if so how?

Remove one of the mirrored drives, place it to one side, perform an upgrade to nw65/sp3 on the single drive still in the server.

If the upgrade proves successful, replace the removed drive and let the mirroring re-sync (ie/ both drives end up on sp3)

If the upgrade is un-successful, remove the upgraded sp3 drive, and replace with the original sp2 drive, reboot server and have it boot back up to sp2 - Once settled, replace the sp3 drive, have it re-sync back to sp2.

The server is not in production, only a test box at this stage.

I've already had bit of a play with trying to achieve/test the above and trashed the array/drives twice now :)

Would be good to know if this manoeuvre could be performed if needed?

Cheers all.

Re: Smart Array 641 & Mirroring

Bart Vanden Driessche — Thu, 31 Mar 2005 03:09:55 GMT

There is a difference in the mirrored disc you remove. I will try to explain this.

You have a good config. You want to update/do something. You want to remove 1 disc of the mirror set and boot of the other. In this case you should remove the first disc (lowest scsi id), and boot from the second disc only.

If all things go wrong, you turn off the server and remove the second mirrored disc. At that time no discs are in the server. You insert back the first "spare" disc in it's original location. At that time you will be able to boot from the mirrored volume (1 disc). When the system is booted, you insert the second disc to initiate a rebuilt.

This setup works with me, in different servers.

Re: Smart Array 641 & Mirroring

itadmin_2 — Mon, 07 Nov 2005 17:12:02 GMT

Thanks for your reply.

Any reason as to why what disk gets pulled first?

why remove scsi-0 and boot from scsi-1, as opposed to remove scsi-1 and boot from scsi-0?

Cheers