Smart Array 641

[Ed Luna]

We have 2 identical HP ML350 G4 servers with 641 Smart Array Controllers... the only difference between the two machines is the configuration of the Array's. One is setup as Mirrored four 73 gig drives (2 logicals) and the other is setup as RAID 5 with five 73 gig drives (one logical). The RAID 5 server is a fully functioning web server with web sites and data that we must retain. The RAID 5 server also performs double duty as a hardware backup for the mirrored server in the event of a hardware failure... in other words, protection from a total loss of the mirrored server (our Domain Controller) by temporarily sacrificing the web server, and using it as the Domain Controller. bTw... it's SBS 2003.

We would like to test our disaster recovery procedure by removing the 5 drives from the RAID 5 server and replacing them with 4 new 73 gig drives and then performing a bare metal restore of the mirrored server to what was the RAID 5 server. So far no problem, we are certain we could do that easily (famous last words).

The question is... "what happens after the test when we return the five 73 gig drives to their original server (the web server) and then attempt a boot? The bare metal restore would have necessitated our changing the setup of the 641 from the original RAID 5 to mirrored. Will the controller need to be reconfigured back to RAID 5 prior to attempting a boot or will the controller be smart enough to recognize the old RAID 5 configuration (from the disks?) and reconfigure itself accordingly? The worst case scenario says the 641 will reset and wipe the 5 drives containing our web sites clean, and we can't let that happen.

Any ideas/direction is greatly appreciated.

Thanks

[Jimmy Vance · Accepted solution]

The Smart Array RAID configuration is stored in a RIS area on each disk.

Power the system down normally, remove the existing drives noting the bay they are currently in. Install the new disks and do you bare metal restore to the new disks.

When your done testing, power down, re-install the original drives in the correct drive bay and power back up.

I've done this many many times with various Smart Array controllers and have never lost any data.

As always, be safe and make sure you have a good data backup just in case something does go wrong.....

[Ed Luna]

Thank you.

I'm doing a full backup now and will conduct the full test of the disaster recovery plan tomorrow.

Thanks again.