2009/12/12 Christopher G. Stach II <c...@ldsys.net>: > ----- "Kenni Lund" <ke...@kelu.dk> wrote: > >> I'm also very interested in how to make backups of Windows guests on >> LVM. But will the shadow copy feature in amanda not only backup the >> files within the Windows machine? I don't think I fully understand >> the >> method - How do you then do a full restore, eg. with no working >> Windows machine? Would you then have to do a clean install of Windows >> in order to get the partition and bootloader setup correctly, after >> which you can do the restore by overwriting all files? > > You can just shut down the VM, make a snapshot, start the VM, dd the > snapshot, and finally drop the snapshot. > > Or, if that's too much downtime, you can xm save, snapshot, copy save > dumpfile, xm restore, dd snapshot, backup dumpfile, and clean up. > > If that's too much downtime, you can xm pause, snapshot, xm unpause, etc., > but you will have issues with your restore because it will look like the VM > crashed and you may or may not lose data.
Yeah, that's the problem. AFAIK if I want to take advantage of using LVM directly for Windows guests, I'll have to do a full dump with dd of the image/snapshot, including any unused bits...eventually combined with some compressing, but still. If I use a Linux filesystem on top of LVM and store the Windows guest in an image on this filesystem, the overall I/O performance will be lower, but I'll only have to backup data which are actually in use, due to sparse mode and/or the qcow2 image format (I'm using KVM). This is quite relevant if some machines have 200GB allocated HDD space, but only actively uses 30GB. > Personally, I only back up data and never have useful data on a Windows > installation volume (or even a native Windows volume, if I can help it). I > can reimage a Windows machine with a single command and it only takes a few > minutes. (Hint: use Sysprep.) Besides, reinstalling Windows machines is > better than restoring them since they progressively bit rot. I agree, I already have backups of the important data, but some of these machines runs some old legacy software, which I for sure don't want to setup again unless it's extremely critical. Also, what I want is a minimal monthly full backup of each virtual machine, from which any of my (less technical) colleagues can restore to another physical server by following some simple guidelines. I think I'll stick with the extra layers (filesystem+image) for now to keep the setup simple and to keep the backups small. But thanks for your input. Best Regards Kenni Lund _______________________________________________ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
