SANCopy with Microsoft Windows 2003 Clustering

Question

Hello,

Any special considerations I should be aware of with migrating LUNs controlled by Microsoft Clustering service?
I have done several SANCopy migrations before and under regular windows file system and had no issues; however, I read some concerns in forums about how Microsoft Cluster Service handles NEW LUNs.

Here is how I usually performed SANCopy Migrations:

- Connect server to both Arrays (one HBA connected to each array).
- Put the server on the destination storage group.
- Connect both source /destination Storage Group to SP that owns source/destinations LUNs.
- Perform successful SANCopy copy session.
- Remove server from source Storage Group, reboot server and then server picks up the destination LUN with same drive letter as source LUN.
I don`t know if it will behave the same way under clustering service or not since there is another layer of adding the resource under the cluster service.

Any thoughts appreciated.

dynamox · Answer

i would not allow the host to see its LUNs on destination array at the same time it has access to source LUNs. Setup a dummy storage group and place your target LUNs there.

1) Perform initial bulk copy
2) shutdown cluster nodes
3) Perform final copy (should be incremental)
3) make LUNs visible to cluster nodes on target array
4) remove LUNs from cluster nodes on source array
5) boot one cluster node, verify cluster services started ok, drive letters ..etc
6) bring remaining cluster nodes online.

MS Clustering relies on disk signatures to discover physical resources, since you are doing block copy that information will end up on the target array.

AranH1 · Answer

I have migrated multiple Windows 2003 clusters using SANCopy. Dynamox is correct in his steps and the only thing I did differently was swap steps 3 and 4.

Since SANCopy is a block level copy the disk signature will remain the same. When I booted up the first node of the cluster after the migration it came up and brought all the disks online like nothing had changed, and from a Windows perspective nothing had. Like magic!

kemc1 · Answer

Hello, How about the SANcopy session? Do you remove the SANCopy session before or after you present the target LUNs to the host? Thanks-

dynamox · Answer

i remove after LUNs have been presented and system came up ok because i want to be able to 're-sync' it just in case it did not come up right and system admin wants to try again.

au_aaron · Answer

Sorry to bring this thread back up from the dead...I just have a few questions surrounding this and MSCS services.

Do I need to take the cluster groups offline, prior to shutting the clusters down?

I intend to shut the clusters down, do a full san copy - rezone/change storage groups as necessary and then bring up one cluster node, check all is well..and then bring up the other one.

NB: The quorum is on the SAN as well which will need to be migrated too...hence the full shutdown...hoping this doesn't really change anything as disk signatures, etc are all copied over..

I've been reading around that people are taking resource groups offline prior to shutting everything down.

Just wanted some thoughts on that.

Cheers

CLARiiON

SANCopy with Microsoft Windows 2003 Clustering

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