On Tue, 14 Apr 2015 18:14:31 +0300 Reco <recoverym4n@gmail.com> wrote: > Hi. > > On Tue, Apr 14, 2015 at 04:01:02PM +0200, Petter Adsen wrote: > > I'm using LVM as storage for virtual machines, and would like to > > share a PV between two machines with iSCSI to be able to migrate > > the VM's. > > I did the thing some time ago. It worked, although I used ietd and not > today's tgtd. The main reason was - ietd had configuration file, tdtd > had not (as in 'our daemon does not need config at all, use tdtadm'). I've already set up iSCSI, and went with ietd, too. To be fair, I didn't know about tgtd :) > > Wikipedia says this: > > "The LVM will also work in a shared-storage cluster (where disks > > holding the PVs are shared between multiple host computers), but > > requires an additional daemon to propagate state changes between > > cluster nodes." > > > > But nothing else. Is the clvm (with dependencies) package > > everything I need to do this? Or would I need to mess with all > > sorts of clustering stuff to get that working? > > Not strictly as the main role of clvm is to guarantee that one LV will > always be used by one node. Secondary role of clvm is to handle LV > addition and removal by principle of least surprise. I.e. lvcreate on > node one should add the same LV on node two. That sounds reasonable. > > 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. Thank you for the advice! Petter -- "I'm ionized" "Are you sure?" "I'm positive."
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