[CentOS-virt] Shared Storage Options

[Brett Worth]

Hello all.

I would like to canvas some opinions on options for shared storage in a Xen cluster.  So 
far I've experimented with using iSCSI and clvm which mixed success.

The primary concern I have with both of these options is that there seems to be no obvious 
way to ensure exclusive access to the LUN/device to the VM I want to run.  On a couple of 
occasions during my playing I've accidentally started the same VM on two servers and 
corrupted the said filesystem.

I've tried setting up GFS but I don't think I'm smart enough to do that.  The fencing has 
me baffled.  In fact fencing had me baffled with clvm but I somehow managed to trick it 
into working though probably not how it's supposed to.

I'd be happy to persist with either of the above methods if I could work out how to lock 
the device.  Can anyone offer some advice?

Regards
Brett Worth