topic Re: what state must be the VG lock ? in Operating System - HP-UX

what state must be the VG lock ?

Jdamian — Thu, 12 Jul 2007 14:21:58 GMT

Hi

In my cluster I defined a VG lock. That VG has just one PV and holds no service (it is included in no package).

That VG must be activated always as /dev/vg00 and other non-cluster VGs (/etc/lvmrc)?

Must it be deactivated and SG will activate when necessary?

I'm a mess

Re: what state must be the VG lock ?

Torsten. — Thu, 12 Jul 2007 14:24:19 GMT

The cluster lock VG could be a "normal" but shared VG. The information is set in the VG configuration area. You may use a "unused" VG too, but all servers must have access to it.

Re: what state must be the VG lock ?

Todd McDaniel_1 — Thu, 12 Jul 2007 14:38:32 GMT

Oscar,

No it doesnt need to be part of any MCSG package nor does it need to be "managed" by SG.

As Torsten said, it only has to be made up of shared disks that can be seen by all boxes in the cluster. Since yours is a VG containing the disk(s) instead of just a cluster lock disk, I believe the VG needs to be defined on all boxes in the cluster.

Re: what state must be the VG lock ?

Faizer Jameel — Sat, 14 Jul 2007 09:23:53 GMT

Hi all

I have been able to start and stop my cluster many times and it works fine with a vg configured with a lock disk shared by both my nodes.

Query for a better understanding.

Does this vg holding the lock disk be in vgactivated mode or not.
[ when I do a vgdisplay it says the vg is not activated] this disk is visible on both he nodes.
Thanks
Faizer

Re: what state must be the VG lock ?

Todd McDaniel_1 — Mon, 16 Jul 2007 10:18:54 GMT

Oscar,

Here is a great link to a mcsg manual.

http://docs.hp.com/en/B3936-90117/index.html

it is also available in pdf form on that page...

Re: what state must be the VG lock ?

Kevin Wright — Thu, 02 Aug 2007 01:14:23 GMT

it does not need to be activated, just cluster awarey.

Re: what state must be the VG lock ?

Stephen Doud — Fri, 03 Aug 2007 07:10:07 GMT

I agree with Kevin. The lock VG does not have to be activated for Serviceguard to use it.
Serviceguard does not use the LVM stack when it needs to interact with the cluster lock structure, one the structure is installed using cmapplyconf.

Re: what state must be the VG lock ?

manish_csc — Thu, 09 Aug 2007 20:20:26 GMT

Hi,
Cluster lock disk used only to avoid split brain sindrome while there is a node failure.

Cluster lock disk not necessary part of cluster VG.

Thanks

Re: what state must be the VG lock ?

whiteknight — Thu, 09 Aug 2007 20:52:39 GMT

The purpose of the cluster lock is to ensure that only one new cluster is
formed in the event that exactly half of the previously clustered nodes
try to form a new cluster. It is critical that only one new cluster is formed
and that it alone has access to the disks specified in its packages. You can
specify either a lock disk or a quorum server as the cluster lock.
A one-node cluster does not require a lock. Two-node clusters require the
use of a cluster lock, but the lock is recommended for larger clusters as
well. Clusters larger than 4 nodes can only use a quorum server as the
cluster lock.

You can outside of non cluster VGs. just treat as normal pv.

Re: what state must be the VG lock ?

Jdamian — Mon, 20 Aug 2007 03:34:53 GMT

Thanx everyone