2 node cluster SAN port change

[brian_31]

Greetings!

Environment HP-UX 11.11 (SG ver 11.16) on EMC. There are some SAN ports change happening and we expect some PATH change in the device files.

1. from the cluster point of view what are the changes i can expect and what should i plan for? (will the lock disk change?) since that is on SAN now?

2. if the device files change, then what are the steps i should do from the LVM standpoint?

3. If the new device maintains the same path, then i assume there would be no change- correct?

Please clarify!

Cheers..

Brian

[Steven E. Protter]

Shalom Brian,

1. If disk device files change, you will want your system down and you should vgexport the volume groups before this happens.

2. You will depending on the change need to vgimport the volume groups, change the cluster configuration via cmquerycl/cmcheckconf/cmapplyconf SG documented procedure.

3. Correct. Not very likely based on what I read.

SEP

[Vishu]

Hi Brian,

1. You need to halt your cluster to do this activity as you can't do this with online cluster with your cluster lock disk accessible.

2. You need to reboot your server, followed by insf and ioscan command to make the new device files available to server and from LVM, you need to create mapfile by vgexport(with -s option) on all of your VGs on SAN disks.

3. yes, if device files remain same then nothing need to be done.

[brian_31]

Vishnu

Cluster lock disk is on SAN, but that is NOT going to be changed. So why would this not be done online. Could you please clarify?

Thanks

Brian

[Stephen Doud]

If the SAN port configuration change results in new special file paths for the LVM volume groups used by the cluster, you will have to export and re-import the cluster VGs in /etc/lvmtab - on each node so affected.

The FORUM search will help you find a thread that describes how to vgexport and import the VGs.

After doing so, note that the cluster binary file maintains the special file path to the cluster lock disk, so if altering the SAN ports results in a new special file mapping to the cluster lock disk, you will have to edit the cluster ASCII file with that new path and cmapplyconf it while the cluster is down (unless this is SG A.11.19).

Theses should be the only tasks you need to add to your procedure. The other SG cluster and package files do not reference device special files.

[Vishu]

Hi Brian,

can you first tell me how you are sure that device files are not going to change. Like are you going to perform rmsf on all the previous device files after unmasking your storage port.

But, if you are not goin to do this then your device files would change for sure. and you have to follow the same procedure stephen mentioned.

and in case, your device files changed then access to the cluster lock disk is lost and you know the worst that can happen when cluster disk lost.


P.S. please assign points to all if you think you got your answer.