I''m working on a project where we''ll be deploying SLES11 xen servers in pairs to remote sites. The goal is to run VMs on each server, but have the VM''s disks synced to the other server in case of failure. There will not be a SAN, only local storage on each server. The VM disks will be sparse disk files. We were looking at a product that could sync live disks to some type of image, but they don''t support linux or NSS volumes, which we use both. I''ve looked at DRBD to create a shared file system with the local disks, but from what I read, one system is the primary. It didn''t seem like you could write to the same disk from both nodes, which we need to do. Server1 would run VM1 and VM2. Server2 would run VM3 and VM4. If something happened to Server1 we want to bring VM1 and VM2 up on Server2 in a state as close as possible to when Server1 went down. Hopefully all of that made sense. Anyone have any suggestions? Thanks, James _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Friday 09 July 2010 15:02:27 James Pifer wrote:> I''m working on a project where we''ll be deploying SLES11 xen servers in > pairs to remote sites. The goal is to run VMs on each server, but have > the VM''s disks synced to the other server in case of failure. There will > not be a SAN, only local storage on each server. > > The VM disks will be sparse disk files. > > We were looking at a product that could sync live disks to some type of > image, but they don''t support linux or NSS volumes, which we use both. > > I''ve looked at DRBD to create a shared file system with the local disks, > but from what I read, one system is the primary. It didn''t seem like you > could write to the same disk from both nodes, which we need to do. > > Server1 would run VM1 and VM2. > Server2 would run VM3 and VM4. > > If something happened to Server1 we want to bring VM1 and VM2 up on > Server2 in a state as close as possible to when Server1 went down. > > Hopefully all of that made sense. Anyone have any suggestions? > > Thanks, > James > > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users >I don''t see what the problem with DRBD would be, it would be the ideal solution for your problem. Why do you need to write to the other DRBD node? There is by the way a DBD document on their site that explains how you can combine DRBD and Xen, but that is definitely not the only way. Rgds, Bart _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
> > > > I don''t see what the problem with DRBD would be, it would be the ideal > solution for your problem. Why do you need to write to the other DRBD node? > There is by the way a DBD document on their site that explains how you can > combine DRBD and Xen, but that is definitely not the only way. > > Rgds, > > BartI think I found the document you are referring to. Both servers will run VMs, so wouldn''t they both need to write to the DRBD node? I don''t have a full understanding of DRBD, so I may be misstating it. Using DRBD with xen, would each VM use a separate drbd node for it''s disk, or would it be a large DRBD node using file based images? I''m still reading.... Thanks, James _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Friday 09 July 2010 16:37:15 James Pifer wrote:> > I don''t see what the problem with DRBD would be, it would be the ideal > > solution for your problem. Why do you need to write to the other DRBD > > node? There is by the way a DBD document on their site that explains how > > you can combine DRBD and Xen, but that is definitely not the only way. > > > > Rgds, > > > > Bart > > I think I found the document you are referring to. > > Both servers will run VMs, so wouldn''t they both need to write to the > DRBD node? I don''t have a full understanding of DRBD, so I may be > misstating it. > > Using DRBD with xen, would each VM use a separate drbd node for it''s > disk, or would it be a large DRBD node using file based images? I''m > still reading.... > > Thanks, > James >OK, well in that case you could define two DRBD resources and have one server being active for the one resource while being passive for the other. The resources then individually synd to the other node. The Ganeti project might be interesing for you as well. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users