Upgrading physical disks in an HP MSA500 using MS Clustering

[snowy600]

Hi

I have a question regarding swapping out (upgrading) physical disks on an HP SAN which holds Exchange 2003 data.

This system is running MS Exchange 2003 in a 2 node clustered configuration.

The Exchange database is held on shared storage (HP SAN MSA 500). The logical drive that holds the Exchange data consists of 10 x 72 GB Ultra320 SCSI drives which are in a RAID 1+0 configuration. This drive letter is assigned the letter T: and is a presented as a Data Disk Resource within the MS Cluster.

I need to upgrade these 72 Gig drives to 10 x 300 Gig drives in a RAID 5 Configuration. There is also an extra disk that is used as an online spare. This makes 11 drives in total.

I've looked around to try and find an official upgrade path but can't eem to find anything.
I plan to perform the upgrade as follows but I have concerns regarding the Data Disk Resource within the Cluster administrator.

1. Take a full system backup of all Exchange nodes and shared storage to tape.
2. Put the cluster service on the 2nd (passive) node into a disabled state.
3. Stop the Exchange services using Cluster Administrator on the active node 1 but make sure that the Data Disk Resource is still running.
4. Take a flat file copy of the Exchange database folder from the shared storage (MSA500) and temporarily store it onto the local physical drives on node 1.
5. Set all the cluster services on node 1 to disabled so that they won't try and start on a server reboot.
6. Shutdown both nodes.
7. Remove the 11 x 72 Gig drives on the MSA500.
8. Insert the 11 x 300 Gig drives into the MSA500.
9. Power on node 1.
10. Go into the HP ACU util and configure 10 of the 300 Gig drives into a RAID 5 config and the 1 additional 300 Gig drive as an online spare for that array.
11. Go into MS Disk Administrator and assign that logical drive the letter T:
12. Start the cluster service and only start the Data Disk Resource. Hopefully the service will start and see the new logical drive as it's been assigned the same drive letter as before.
13. Copy the flat files from the local disk on node 1 to the T: drive on the shared storage.
Start all the other cluster services including Exchange.
14. Once node 1 is online turn on node 2 and configure the cluster service to start.
15. Test failover.

As I mentioned above my concern is the original Data Disk Resource within the Cluster Administrator recognising the new logical drive even though the drive letter is the same.

Could you confirm whether the above approach will work or do I need to perform some additional tasks?

Many thanks in advance.

Martin

[Rune J. Winje]

The cluster recognizes a particular cluster disk by it's disk signature and disk size.

The software that runs on top of the cluster may also need the disk letter to match - Exchange does of course mind if you change the drive letter, so this should also match.

So to make a short story long

1) Pause the second node to not get unwanted failovers to this (passive) node.
2) Take the exchange group offline in the cluster - and have only the disks online.
3) Set Exchange services to manual startup on both nodes and stop the services.
4) Take a full backup including file security of the Exchange group's disks.
5) Remove old disks
6) Add new disks - probably some reboots needed (reason why we put Exchange on manual startup in 3)
7) Restore full content to new disks
8) Use cluster admin to add the disks to the cluster as new shared disk with a new driveletter U:\
9) Use clusterrecovery.exe (from 2003 reskit)to swap the old T:\ (greyed out at this point since disks are removed) with the new U:\
10) Finished - Start Exchange, Exhchange is unaware that T:\ is now a new set of disks since the drive letter, and disk signature is the same. The cluster is happy since the clusterrecovery.exe makes the cluster accept the size change of the T:\ drive.
11) Tidy up step is to delete the U:\ drive from the cluster.


Cheers,
Rune