Backup and restoration of WSL1 files

[user562]

Are backups using Veeam Agent for Windows (v5.0.1.4584) able to back up and restore entire WSL1 filesystems (in particular, with an Ubuntu guest)? For WSL2, restoring is presumably trivial, since the contents of the guest are stored in a virtual-drive file. However, for WSL1, the files instead exist as Windows files with NTFS extended attributes that correspond with Linux permissions and properties. Are these extended attributes retained by Veeam, and is it possible to restore them?

From what I can tell, the Veeam backups may not retain the Linux permissions, but it is not clear to me if that is because Veeam does not retain them or because of the way I am viewing/copying the files. I have attempted to restore both through the Veeam Agent interface (does not work due to filepath length limitation) as well as robocopy (file contents are restored, but permissions are lost; files appear to have the octal value 000).

(The recommended way to back up and restore is to use `wsl --export` and `wsl --import` to a tar file; however, this is assuming that this has not been done.)

[HannesK]

Hello,
and welcome to the forums.

I remember the issues you mention when I tested WSL some years ago. So it looks like expected limitations to me.

Best regards,
Hannes

[user562]

Thank you, that makes sense. Do you have an inkling if it is because the NTFS extended attributes are not stored during the backup stage, or are they not retrieved during recovery? I am wondering if there is a workaround if it is the latter. (e.g., restoration of files with long paths does not work in some Veeam software but can be circumvented by opening in Explorer and copying another way, so those files are not lost at backup)

Does this limitation extend to other forms of NTFS extended attributes?