Support for vhdx or raw image format


It would be great if vhdx or raw image format is introduced for image backup in urbackup as this will remove the 2TB image backup limitation on common filesystem like - ext4, xfs etc

Also more than 2TB drives like 4TB, and 8TB are available in the market which makes this another reason to have improvement on the limitation with urbackup so that more than 2 TB drives can be backed up for data images.

Please vote for this feature


Isn’t this possible with ZFS raw images?


yes it is, but that makes it dependable to only zfs or btrfs which is not suitable for all scenarios, for example I have a scale-out storage with xfs filesystem and another one with ext4.

ZFS is limited to single physical box and does not scale-out when required.

Adding raw or vhdx image format instead of vhd will remove this dependability and then any filesystem can be used to backup image more than 2 TB.


XFS has reflink support in its newest versions and they are about to not mark it experimental anymore, so UrBackup will support raw images on XFS at some point (and perhaps ReFS on Windows).

But ext4 won’t and you don’t really want a full copy for each incremental file backup, do you?


My only concern is with the 2TB limitation, if that can be fixed in XFS then that will work,

Is there any limitation when we use vhdx for image backups instead of vhd?


Someone has to implement it. It is work :wink:


I’m concerned about the 2TB limit also, but I am unsure if XFS is the direction I would prefer to head. If VHDX’s were to be used, I think that would meet the functional needs I’m looking for, but I also am aiming to use UrBackup with ZFS too. So ZFS is tasty for me too.

I’m interested in using UrBackup for Win/Lin/Mac purposes, so using methods that are more platform-agnostic is preferable. But I like ZFS a lot for its performance and other advanced features, but I am not familiar with XFS.

What are the current thoughts on (an) effective avenue(s) to address this functional need? (larger than 2TB image backups).


Actually I had a thought. Is it possible to use qcow2 file format for this? That might also enable the infinite incremental as seen on btrfs (not sure). Also, if we could backup to qcow2 file formats, that would be tasty for spinning up LinuxKVM VMs from the backup files! :smiley:

Or is there a good reason qcow2 file format might not work? I dunno…