Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
I do need live migration but not as a failover. So the migration will be manual and not automatic. In that case I would at some point have to run in primary/primary. Is the cluster fs only for shared storage configurations? Also what ensures that the VMs disk is only being accesses by one hypervisor node at a time? Would libvirt or drbd controll/ensurs that or is it up to me? Thats my main concern once I know this is feasible and the best route. Thanks - Trey On Oct 30, 2011 2:41 PM, "Bart Coninckx" <bart.coninckx at telenet.be> wrote: > On 10/30/11 20:34, Trey Dockendorf wrote: > >> >> >> Hi, >> >> a cluster software like Pacemaker could serve your purpose very >> well. Do incorporate STONITH though, as you will need dual primary >> DRBD. >> Mind you Pacemaker is NOT easy, requires a lot of study and reading. >> >> Share image files could be done with OCFS2 for example (or any >> clustering file system). You then need to create a Pacemaker >> resource handling this. Personally I never used OCFS2, but there are >> lots of eaxmples around. >> >> HTH, >> >> B. >> >> Looking at the man page for STONITH I'm not sure I understand how to >> incorporate that into this particular situation. When I put DRBD in >> dual primary that will be only for the purpose of live migration, but I >> don't really plan to use live migrations at first for failover. My >> initial purpose is for maintenance, to allow me to reboot one node >> (after kernel update) and move all the VMs to the other node. Once I've >> got all that working smoothly then I'd move to having it serve a >> failover function. >> > > If you don't need live migration, you can safely forget about dual > primary. It is actually even better since it is (or rather can be) a can or > worms. > > No reason to go for OCFS2 either, unless you want shared storage for your > config files (though NFS might serve that purpose too). > LVM with a regular file system is fine, very good for backup. > > But do keep in mind that a master/slave system (or primary/secondary DRBD) > will in no way allow you to live migrate. You can however always add it > later, though converting from ext4 to OCFS2 probably will require backup > and restore. > > Would OCFS2 be used in conjunction with DRBD? From a few articles I've >> found, I thought that what could be done is create a LVM that stores all >> the qcow2 images (part of my current deployment already) named >> lv_vmstore. Since I'm running CentOS 6 I've been formatting that ext4. >> Would I not then use DRBD to replicate lv_vmstore across both nodes? >> >> One catch to all this I think I forgot to include in my initial email is >> I have no shared storage. I only have 2 physical hosts with >> approximately 1TB isolated for lv_vmstore. Someday once budgets allow I >> may have a SAN, but for now I am trying to facilitate live migration >> without one. >> > > DRBD is a technology that would allow you to be without a SAN. > But do you or don't you need live migration (as you now mention you do)? > > Thanks >> - Trey >> > > B. > > > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.linbit.com/pipermail/drbd-user/attachments/20111030/4bbea63b/attachment.htm>