Good points, especially the NAS/SAN being the single point of failure. DRBD and OCFS work well together, I had a play around with those as well.
On 13 May 2010 11:45, Jake Anderson <ya...@vapourforge.com> wrote: > Personally I'd go with the max memory setup you were talking about but I > wouldn't bother with the NAS. > With only 2 nodes DRBD is fairly easy to setup, it gives you complete > synchronisation of partitions, IE when you write in one place that write > will only come back as ok if it has made it across the network and been > written to disk on the remote machine (depending on settings). If your ok > with a manual change over with a little downtime (in the case of an > intentional transition between servers) I'd put something like ext4 on a LVM > ontop of the DRBD partition mainly to keep things fairly simple. to migrate > machines you shutdown the guests, unmount the file system on host A, mount > it on host B and start the guests there > If you want seemless transitions your going to want something like OCFS or > somesuch for the file system, which gives you the ability to have it mounted > at both locations and hence live migration, you might be able to feed your > VM's raw lvm partions on the DRBD system and not bother with OCFS which > would make life easier but I haven't looked into that. > Upside to this system is you don't have a NAS that can go down as a single > point failure. > > For your offsite backup I'd then snapshot the machines and LVM's and rsync > them to your remote location. > rsync of the memory snapshot could consume a decent amount of bandwidth, > its probably going to be pretty volatile, if you can shutdown the guest > snapshot its disk then boot it back up again then the rsync traffic should > only be a little over the quantity of changes made to the disk IE files > added/changed, so not much more than your existing offsite backup needs. > > > I'm using KVM for my virtuilisation and it seems to be working well, very > simple to use and the host has a full OS there to do whatever you want with. > Currently I run mysql on the host to get a bit more performance out of the > machines (with a ~20Gb database) and the application servers in VM's on the > same machine, with mysql replication to pass the data between the hosts. > > -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
