Re: Sharing LVM storage
On Wed, Apr 15, 2015 at 08:41:07AM +0200, Petter Adsen wrote:
> > > I just want to try it out to see how it works, it's not something I
> > > need by any stretch of the imagination, so there's a limit to how
> > > far down that rabbit-hole I want to go.
> > As long as you don't forget to run lvscan on partner node after doing
> > basically anything with LV on main node - you should be OK.
> > But just to be on the safe side - don't export PV via iSCSI. Export
> > LVs.
> May I ask why, so I don't mess anything up? I was thinking of exporting
> maybe my VM VG, so that all LV's for VM's were available to both
> machines. Or just the device itself.
That's the main reason. Creating PV-via-iSCSI configuration from the
scratch is simple. It's maintaining it (or worse - changing it) is
For example, imagine the need to migrate all LVs from one PV to another.
Without downtime, of course. Is it doable - yes. Is it simple - no.
Besides, there's a *small* matter of backups, and in cases such as this
I prefer straightforward approach. I.e. there's "storage" host, and
there are "VM" hosts. "Storage" host provides LVs as /dev/sd* devices to
"VM" hosts *and* manages backups. "VM" hosts merely do their VM thing.