On Wed, Apr 01, 2015 at 10:00:43AM -0700, Scott Baker wrote: > We're in the process of building a new VM cluster that look similar to this: > > ----- ----- > |VM1| |VM2| > ----- ----- > \ NFS / > --------- > |Backend| > --------- > > Are there any official recommendations on:
Not "official" but ... > 1) NFS export/mount options I used all defaults. If you wish to migrate VMs, then you *must* use cache=none for the VMs, as explained here: http://wiki.qemu.org/Migration/Storage > 2) File system choice I used ext4, but any decent fs should work fine. Avoid btrfs. > 3) VM image format (qcow vs raw) It turned out that qcow2 has an amazing susceptibility to corruption, especially when a node crashes. So I converted my VMs to raw, because at least if you get corruption it doesn't make the entire VM file unreadable. > 4) How to backup rsync -av /var/lib/libvirt/images /mnt/backups - - - I was using nfs on my cluster[1], but I'm no longer using it. Why? Because it's just way too slow over standard gigabit ethernet. [1] https://rwmj.wordpress.com/2014/04/28/caseless-virtualization-cluster-part-5/ I also used iscsi for a while, backed with logical volumes. The iscsi management tools are absolutely hideous, but the performance and reliability were far better (using the precise same hardware). - - - Anyway, I'm now using local disks attached to each node, and just storing my VMs there. Of course this means I can't easily migrate VMs, but the performance is far superior. My VMs are now fully transitioned to cloud-like "cattle", using NFS mounts for shared data (basically NFS-mounted /home and a few other mounts), so migration isn't really much of an issue for me now. My cloud management software in case anyone is interested: http://git.annexia.org/?p=mclu.git;a=summary Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-top is 'top' for virtual machines. Tiny program with many powerful monitoring features, net stats, disk stats, logging, etc. http://people.redhat.com/~rjones/virt-top _______________________________________________ virt mailing list virt@lists.fedoraproject.org https://admin.fedoraproject.org/mailman/listinfo/virt
