vgcfgbackup for vglock

[Andrew R.]

Hello all...

Can I backup my vglock while the cluster is running,currently th VG is deactivated. Can I activate it and back it up, if I can does it have to be in Exclusive mode or not ??


Thanks a lot

[melvyn burnard · Accepted solution]

To use vgcfgbackup on a vg, it must be activated on the node on which you are going to issue the command.
If this is a shared or cluster vg, then you normally activate it via the package, in exclusive mode.
If the package is active on another node, you could do:
vgchange -a r vglock
vgcfgbackup vglock
vgchange -a n vglock

[Santosh Nair_1]

Andrew,

The answer to all your questions is yes. You can do a vgcfgbackup, the VG has to be activated in exclusive mode and this can be done without affecting the SG packages. Obviously you can't activate the VG on more than one node, but then why would you want to?

-Santosh

[Santosh Nair_1]

Melvyn,

I think there's a typo in the commands you've given, it should be vgchange -a e vglock and not vgchange -a r vglock.

-Santosh

[melvyn burnard]

No I am not wrong.
You can activate the VG in READ-ONLY mode using the -r for the short time this vgcfgbackup is to be run.

[Santosh Nair_1]

Melyvn,

I apologize, I misread your comments. I though you were saying that vgchange -a r vglock would activate the VG in exclusive mode.

-Santosh

[Sanjay_6]

Hi Andrew,

I think what your are trying to say is that when your cluster is up, your lock vg is not activated on any node because it is not associated with any package. If that is the case you can activate the VG on any node and take a vgcfgbackup as melvyn has suggested. you don't have to do this on both the nodes, one will be sufficient as the idea is to restore the VG conf if you need to replace the lock disk. However you can still do it on both the nodes. To do that, first activate the VG on one node, take vgcfgbackup, deactivate the VG, activate it on another node, take vgcfgbackup and then deactivate. Thsi whole thing is assuming that VG is not getting activated on Cluster/Package startup.

In case the VG is getting activated on cluster startup by any package, it would be already be activated on one of the nodes. So you can take vgcfgbackup on that node. To take the vgcfgbackup for the lock VG on another node in this case, you'll have to move the package to another node so that the VG get's activated on that node. You cannot access the VG on the second node, if it is already active on the first node (through the package).

You can do all this even when the Clsuter is running. In fact you an access the lock VG only when the cluster is running.

If you want to activate the VG, when the cluster is not running then you have to make the VG cluster non-aware by using "vgchange -c n /dev/vg_lock", then activate it using vgchange, take vgcfgbackup, deactivate it, put the vg back in cluster aware mode, by starting cluster and doing "vgchange -c y /dev/vg_lock". From what i remember in this case you cannot make the vg cluster aware if the cluster is not running.

Hope this helps.

Thanks