Re: [linux-lvm] has anyone used LVM in a HA cluster?

[Patrick Caulfield <caulfield@sistina.com>]

On Thu, May 09, 2002 at 09:54:40AM -0700, Au, Richard wrote:
> Hi,
> 
> I'm wondering if anyone has used LVM in a high-availibility cluster
> where two servers are connected to shared storage (the physical
> volumes).  If so, which cluster solution did you use?  Will there be
> problems if the logical volumes are visable to both servers, even if
> only one of them has them mounted?  Thanks!

Provided you're either using GFS as the file system or being VERY careful to
mount the filesystem on only one node at a time you can do this.

The key is just to be VERY careful. If you need to do any LVM commands you MUST

umount filesystems on all other nodes
vgchange -an on all other nodes

do the LVM metadata changes

vgscan on all nodes
vgchange -ay on all nodes.

The safe thing to do is to have only one node have the LVM commands available to
it (apart from vgscan & vgchange) and be VERY careful.

I'll say that again: Be VERY careful !

patrick