How to reconfigure service guard when disk device file changed

[Printaporn_1]

Hi,

I have 2 nodes service guard with identical hardware. I have to upgrade one server in cluster. Then disk device file will changed.
How can I reconfigure service guard to work after hardware upgrade.
thanks in advance,

[Thayanidhi]

Reconfigure the VG. Make sure the VG name and LV names are same as it was. If you are adding Lv/FS corresponding pkg contrl file needs modification.

Is this PV configured as lock disk?

If yes, modify cluster acsii file and cmapplyconf!

Note: You need to re-import the VG to other node after modification.

Regds
TT

[Duncan Edmonstone]

It very much depends on whether you want all your packages to stay up during the upgrade, and whether you are using a cluster lock disk or not.

The defintion for cluster lock disks in your cmclconfig file cannot be updated while the cluster is running - so if you have a cluster lock disk you may need to stop the cluster, or you will need to take your host out of the cluster during the upgrade.

So thats either:

1) Stop Cluster
2) vgexport appropriate VGs on node to be upgraded
3) Do upgrade
4) vgimport VGs on upgraded node
5) update cmclconfig.ascii with new location for cluster lock disk on upgraded node
6) cmcheckconf & cmapplyconf
7) start cluster
8) TEST FAILOVER!

-or-

1) failover packages and cmhaltnode on node to be upgraded
2) alter cmclconfig.ascii on other node - comment out the node to be upgraded and all associated entries
3) cmcheckconf & cmapplyconf
4) vgexport appropriate VGs on node to be upgraded
5) Do upgrade
6) vgimport VGs on upgraded node
7) update cmclconfig.ascii - add back in upgraded node and update location for cluster lock disk on upgraded node
8) cmcheckconf & cmapplyconf
9) start upgraded node with cmrunnode
10) TEST FAILOVER!

The second option is slightly more complicated, but keeps your apps up for longer...

HTH

Duncan

[Printaporn_1]

Hi Duncan,

We have lock disk and we can shutdown cluster during upgrade.

but I wonder , if we shutdown SG/Disk will umount , how can we do vgexport ?
could you please give me more clear pictures on those LVM tasks.

thank you

[Rita C Workman]

All you would have to do, once you stop your package is:

vgchange -c n /dev/vgname
vgchange -a y /dev/vgname

Then vgexport your device group to a mapfile..
vgexport -v -s -m /etc/lvmconf/vgmapfile /dev/vgname

Now you have your mapfiles that you can use to do your vgimport. And remember to copy these mapfiles to someplace that will not be affected by your server upgrade !

Rgrds,
Rita