You can't do an image backup of a Linux partition

client
1

I’ve been trying to set up Urbackup to backup a Ubuntu 22.04 client using an image backup to backup the client system partition. The file system is btrfs and on installation of the client software I selected option 3 (use the btrfs snapshot facility).

I also have image backups on the server set to default to backup the C drive which I understand automatically translates to root if the client is a Linux client.

I would have thought that this would default to backing up root on the client, but I get an error in the log that ‘no path has been set’ so it aborts the backup.

Urbackupclientctl won’t take ‘/’ as a path name, so the only way I can see of backing up root would be to list all the directories, /etc /home et al.

There is no way to specify a device so you can’t add ‘/dev/nvme0n1p2’ or any other device to urbackupclientctl, so in effect it’s not possible to make an image backup of a Linux machine.

Is my assessment correct? Unless anyone can disabuse me of this opinion, this is my working assumption. If there is a way to do this, I would be grateful if someone could explain this to me, or if I’m right, then confirm that a system image backup can’t be done.

Thanks in advance for any help.

2

In afraid I cannot offer an awful lot of help but just wanted to confirm that setting the backup drive to „C“ for Linux clients is correct. It worked as expected for me so far.

3

I bookmarked this post way back when I was still considering using img backups, maybe you guys find it useful.

4

Hi bedna
Thanks for taking time to reply. The problem is dattobd. I originally tried this but it wouldn’t install. One of the forum entries suggested using a fork of datto and this did install, but urbackup couldn’t find it. As a result of this I re-installed Ubuntu with btrfs, but that doesn’t work either as far as I can see as cited above.

It’s a shame because I think urbackup is the best design of all the backup programs that I’ve tried (and I’ve tried a few now). One reason why I’ve spent so much time trying to get it to work is because it holds out the promise of being the perfect backup solution. Ah well.

5

I feel like this has less to do with btrfs server side and more to do with what you identify as a problem, img backups, or in this case dattodb.

Try going with file backups only and then when you see less “img backups doesn’t work” in the forum, try implementing it again.

Img backups on urbackup seems pretty unstable atm, and me for one would NOT want to rely on an unstable backup solution.

6

For now I can also not recommend to perform image snapshots with dattobd. There is very little attention for this project on behalf of datto inc and there is no real community around it. I waited for a long time to make a move towards Ubuntu 22.04 because they just recently released a version that should work with the new kernel. However it does not seem to be as stable as it was back in Ubuntu 20.04. It wouldn’t surprise me if it would take another year or more until those problems have been solved.

EDIT: And don’t even think about using elastio either. Now that my datto snapshots are gone I tried if elastio works better for me but it’s even worse… I can’t seem to get any images that I can mount…

7

Hi
Thanks for confirming my feeling about Datto. That’s why I decided to re-install Ubuntu with btrfs. It seemed much safer. Sadly that doesn’t work either.

8

Btrfs image backup is not supported. See the limitations section at UrBackup - List of all features of UrBackup .

If you follow bednas link you can also read following:

2.5.x can backup Linux clients (via dattobd only). The use case is e.g. backing up a DigitalOcean instance. It is explicitly not to create image backups of all possible configurations e.g. LVM, mdraid, btrfs, …