Urbackup to Backup/Restore Windows VMs

Hi there,

I stumbled on urbackup while evaluating backup solutions for my virtualized servers. I use KVM with LVM block devices running windows server 2012 R2. I’ve read the features but have a few questions:

  • urbackup supports image and file based backups: How are they stored on the urbackup server? VHD files for the images and files 1:1 as files? What about compression?
  • So if I use image and file based backups for one machine, are the files stored twice? Should I completely skip file based backups when I do image based backups?
  • Does the incremental image based backup update this one VHD? If it does, what are full backups for? So is there only one VHD image? I ask because one may need to go back to a previous image based backup and not the current one.
  • Do I need to boot the restore cd, or can I also install ‘urbackuprestoreclient’ on my host machine? It would be cool to do a restore right to the block device instead of booting up the VM with a virtual ISO etc.
  • Can I create a backup from a LVM block device from the host (something like urbackup_client -i /dev/vg/vm0 -o myimage.vhd)?

Sorry if I asked the obvious or completely misunderstood some things. I’ve not yet tried the software yet I just want to figure out if it matches my requirements.

Thank you!

Andreas

Compression can be made in 2 different ways :

  • Storing backups in VHDz format, which is a compressed VHD file, “mountable” directly from the urbackup server
  • Storing backups to a BTRFS storage or ZFS storage. BTRFS gives the advantage of an integrated snapshot management with UrBackup able to make forever incremental (synthetic backup)

Yes files are stored twice because file backups and image backups are independent. File backup is ACL compliant, ie when you restore files from files backup it restores files and windows ACL. File restore level from image backups is possible from presenting the content from a mounted VHD/VHDz but only from CLI and manual operations (scp, …)

No there are mutliple VHD stored with a big full + small incremental. And you can mount all of them at the required restore point :

urbackupsrv mount-vhd
		Mount VHD file

urbackupsrv assemble
		Assemble VHD(Z) volumes into one disk VHD file

or restore full image at the required point restore as well from booting the restore CD

Maybe it will be possible but with some additional code i think. I’ll be interested with this too, we’re using Proxmox hypervisors (KVM based)

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Hi TomTomGo,

thank you for your replies!

That’s perfectly fine for me, I use ZFS on my servers. The integrated snapshot feature you mentioned does not work directly with ZFS, even though ZFS does support efficient snapshots, right? Is there a technical reason for that, like a feature BTRFS does have over ZFS? Until now I opted for ZFS not only because of it’s feature set and integration in Proxmox and Ubuntu/Debian lately, but also because of its stability. I heard a lot of complains about BTRFS regarding stability without ever having any personal experiences.

Ok, I guess the best option would be to differentiate between system and user data: Using image based backups for the system drive and file based backups for documents.
Is it possible to include/exclude folders for both, file and image based backups?

Same here. I found something in the wiki: https://urbackup.atlassian.net/wiki/display/US/How+to+restore+via+command+line

Start the restore cd (>1.0) or download the binaries from http://buildserver.urbackup.org/restore_cd.tgz (32bit Linux).

This sounds like the binaries can be used from environments other than the restore cd as well.
However, this is restore only. I think doing the backup this way is hard, because urbackup relies on volume shadow copies which are only available from within the windows environment. I know that acronis server backup can backup devices while they’re online but this software is extremely expensive.
What I would like to do is to create a snapshot and do a backup from there. In this case, there’s no need to make usage of VSC because it’s already a block level snapshot. I think this would be a killer feature.

For filesystem choice to use with UrBackup, you can read this very good documentation :

https://www.urbackup.org/administration_manual.html#x1-9100010.7.2

You can include / exclude for file backups only …

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I’ve been using BTRFS (current 6TB) with UrBackup (on Debian 8.x) and haven’t run into any issues that I’m aware of.

Also NetGear uses BTRFS for some of their NAS boxes, so it’s nice to see some bigger companies supporting it.

Yes same setup for me, no problems for the moment …

Synology use it on their NAS boxes also.

I just remembered one self-inflicted issue… don’t mount the btrfs drive with the sync option (which isn’t the default anyway). Doing so will cause excessive disk IO and kill performance.