How to activate a ServiceGuard VG on another Node temporarily

[Ian Dennison_1]

Am trying to activate a VG that is in a ServiceGuard Cluster on another Node in the cluster, to verify that the VG has been imported correctly with the proper lvol map files. I have changed the VG at the source node using "vgchange -S y -c y [vgNAME]" but still cannot activate it at the other site (after making the disks readable at the other site from the Disk Array, of course)

How do I override this, or alternatively how do I verify that the Lvol Map is correct for the Volume Group at the secondary site?

Share and Enjoy! Ian

root@tw03n1v1:/> vgchange -a e /dev/vg_kavtest
vgchange: Warning: Couldn't attach to the volume group physical volume "/dev/disk/disk84":
Invalid argument
vgchange: Activation of volume group "/dev/vg_kavtest" denied by another node in the cluster.
Request on this system conflicts with Activation Mode on remote system.
vgchange: Warning: couldn't query physical volume "/dev/disk/disk84":
The specified path does not correspond to physical volume attached to
this volume group
vgchange: Warning: couldn't query the list of physical volumes.

[Matti_Kurkela · Accepted solution]

"vgchange -S y" means the VG will be shareable, i.e. it can be activated on multiple nodes if all the currently-running cluster nodes agree.

You're trying to activate the VG with "vgchange -a e" which means exclusive activation, i.e. "activate the VG and make sure no other node will be allowed to access it." If the VG is already active on any other node, in any mode, this will obviously fail.

If you want to activate the VG in exclusive mode, you must first deactivate the VG on all other nodes: "vgchange -a n vg_kavtest".

If you want to activate the VG in shared mode, then all the other nodes that have this VG activated must have it in shared mode too, and you must use "vgchange -a s vg_kavtest".

You can directly switch from exclusive mode to shared mode and vice versa, but only when the VG is active on a single node only.

[Ian Dennison_1]

Thanks Matti, perfect answer. Hope I assigned points / kudos correctly. Share and Enjoy! Ian