[Linux-cluster] How to undo vgchange --clustered y?

[Bryn M. Reeves]

On Tue, Mar 01, 2016 at 11:02:11AM -0500, Bob Peterson wrote:
> I had this problem once a long time ago.
> I think what I did was: I exported the LUN on the SAN to a working
> cluster with clvmd, and did vgchange -cn <volgrp> from there. You probably don't
> have that option. You could try vgchange -fff, but I haven't tried it myself
> so I don't know if it will work.

The easiest and safest way to do it is to use lvm2's --config switch
to temporarily disable clustered locking for the vgchange command.

Of course, before doing this, you should check to ensure that the
cluster really is disabled/inquorate or otherwise unusual (or in
the case of an accidental "vgchange -cy" that it doesn't exist :).

The command looks like:

  # vgchange -cn $vgname --config 'global {locking_type = 0}'

Where $vgname is the name of the VG to modify.

If you're on Red Hat and have a portal account there's some
additional detail in the following kbase article:

  https://access.redhat.com/solutions/3618

Regards,
Bryn.