I am currently testing out Urbackup. For that I have a sever (Ubuntu 24.04.3 LTS, UrBackup Version UrBackup 2.5.35) and a client (also Ubuntu 24.04.3 LTS, UrBackup Client Controller v2.5.26.0).
I installed the client via the Server Web UI (Add new Internet/active client) and then the
command. After that I followed the instruction given on the Server GUI.
During installation of the client I had the options:
“1) dattobd volume snapshot kernel module from GitHub -datto/dattobd: kernel module for taking block-level snapshots and incremental backups of Linux block devices (supports image backups and changed block tracking)
2) LVM - Logical Volume Manager snapshots
4) Linux device mapper based snapshots (supports image backups and changed block tracking)
5) Use no snapshot mechanism. Files will be backed up without creating snapshots of them. Images backups will be not supported.
Enter choice (number 1-5, then enter):”
Here I chose option 2.
File Backups and restore work well. Image Backups do not work. The statussays “not supported” and if I tryto trigger a full image backup over the server GUI it says ”Queued backup” but then nothing happens.
I already tried to change the “Volumes to backup” setting.
LVM image backup should work (but won’t have CBT). Currently the scripts aren’t adjusted to allow it. It should not be much work to do so, but no one did it yet and contributed the change (and tested that it works).
Option 4 seems to be the only one with image backup enabled (for me at least, if I have done the setup correctly). Other options sow “image backup status” on the Server GUI as “Disabled”.
But if I want to start a image backup I get: “Request of image backup failed. Reason: Creating shadow copy failed. See client log file for details."
Client logs say:
2026-01-29 07:50:29: ERROR: Creating snapshot of “/dev/sda” failed
2026-01-29 07:50:29: ERROR: File system not supported
2026-01-29 07:50:29: ERROR: Creating shadowcopy of “/dev/sda” failed.
2026-01-29 07:50:29: ERROR: Creating shadow copy failed. See client log file for details.
2026-01-29 10:45:15: ERROR: Creating snapshot of “/dev/sda” failed
2026-01-29 10:45:15: ERROR: File system not supported
2026-01-29 10:45:15: ERROR: Creating shadowcopy of “/dev/sda” failed.
2026-01-29 10:45:15: ERROR: Creating shadow copy failed. See client log file for details.
Is there a way to enable snapshots on option 2 (LVM)?
I am a little confused. Please tell me more about your layout.
/dev/sda is a whole disk - no partitions.
What fdisk partitions (if any) do you have.and what filesystems are on it/them?
The message about “shadow” creation failing implies (to me) windows volume shadow system. Aka VSS. BUT, I thought you had an issue with a Linux client. Maybe the messages have changed recently to use the term ‘shadow’ as the generic term? Hence a contribution to my confusion.
It just occurred to me …..did you actually setup your partition(s)/disk to use LVM when you installed Linux?
I have tried two different ways. When installing the Client and being asked:
“1) dattobd volume snapshot kernel module from GitHub -datto/dattobd: kernel module for taking block-level snapshots and incremental backups of Linux block devices (supports image backups and changed block tracking)
2) LVM - Logical Volume Manager snapshots
4) Linux device mapper based snapshots (supports image backups and changed block tracking)
5) Use no snapshot mechanism. Files will be backed up without creating snapshots of them. Images backups will be not supported.
Enter choice (number 1-5, then enter):”
At first I chose option 2, here the Server GUI said for image backups “not supported”
Then I reinstalled the Client with option 4. That is where I got he error messages from above.
Before running into the wrong directions. This first step is correct, if I want image snapshots I have to chose option 4 and not option 2? If that is correct I will look into your other questions.
Lvm image backups are a achieved by the urbackup making a small, writable logical volume on which “replaces” the original logical volume on which your filesystem is mounted such that….further writes will temporarily go to this new bit . Reads will still come from whichever data blocks contain the correct data.
Then the (now static) logical volume can be copied to the server (with first checking that we don’t transmit stuff we already have at the server).
After which, the logical (static) volume is put back and any mods that occured on the small temp LV are copied to it.
This is all so we can do a backup on a “live/in use” filesystem.
There are caveats. Which is why I want to know about your actual filesystem/s on the client.
I use signal (the app). It permits me to create a temporary name that I can give out via a QR code that allows someone to message me and for me to reply/have a text or voice conversation with.
If you have signal too….then I am happy to give you a QR code a d we can chat and try and resolve your issue.
I have had throat cancer (treatment completed) which means that….I can’t speak for more than about half an hour and then I get fits of coughing.
Just informing you…. NOT requiring sympathy…just patience.
