Prepare for Cluster Migration

[Jacky Wing]

I have a two node cluster with an EVA system. I want to present all the vdisks of the cluster to a third system.
I want to do that since I want to prepare for cluster migration to new systems. I want to be able to present disks and note the paths and ... so I can vgexport / vgimport later on without any surprises.

Am i able to present the vdisks without corrupting the data? all I will be doing is:
- ioscan -fnC disks
- ioscan -m dsf
- vgimport from the old system & be sure that the architecture is preserved
- create directory without activating the volume group & mounting
- preparing cluster configuration and cmcheckconf without cmapplyconf

what do you think?

[Stephen Doud]

Your steps look reasonable. You will probably have to 'zone' the LUNs on the array to appear on the third node.

[melvyn burnard]

at some stage in the plan you WILL have to test whether the devices work by activating the volume group, even if only in read-only mode.
Likewise the directory mount points must be tested

Make sure that the new node has the same SG version and pacth as the existing nodes prior to adding it in to the cluster

[Jacky Wing]

Thank you for replying.
the cluster is not the same, it is a new cluster with new name.
My question is:

- Can I present the luns to the new system, vgimport the architecture from the old system, create the directories, prepare the cluster config, check it ---- All that without disrupting the running cluster.

Does the above actions lead to a corrupted data on the luns? I will not activate the vg nor I will mount the directories.

When all above is done, can I apply the cluster conf (also without disrupting the nodes running?)

[Doug O'Leary · Accepted solution]

Hey;

- Can I present the luns to the new system, vgimport the architecture from the old system, create the directories, prepare the cluster config, check it ---- All that without disrupting the running cluster.

Yes

Does the above actions lead to a corrupted data on the luns? I will not activate the vg nor I will mount the directories.

No

When all above is done, can I apply the cluster conf (also without disrupting the nodes running?)

yes

The cmquerycl, cmcheckconf and cmapplyconf commands don't write to any shared disk. it will check to see if you *have* any shared disks but doesn't write to them at all.

On second thought: you can do all that if you're using a quorum server. If you're not, you'll need a lock disk which, presumably, will be in one of the shared volume groups.

So, short version: you can do all of the above as outlined under the assumption that you're using a quorum server.

HTH;

Doug O'Leary

[Jacky Wing]

Thank you Doug, & all.

Actually I have a 1 GB lun for the lock, I prefer it this way, less prone to errors.

[Jacky Wing]

Thx