restic backup with btrfs /

[Ulli Horlacher <framstag@rus.uni-stuttgart.de>]

restic (https://restic.net/) is a great backup tool but has some
limitations or design flaws: one is, it believes that any subvolume is on a
different filesystem. This means: "restic backup --one-file-system /" will
only backup the root subvolume, but no other subvolumes like /home
/var/spool etc... 

One has to add every subvolume to the argument list. Bad if you 
create new subvolumes and forget to update the backup cronjob.
When you later need to restore a file, there will be none...

My idea is now: I do not backup the original /, but do:

mount --bind / /backup/restic
restic backup /backup/restic
umount /backup/restic

Next evolution step: 
I could recursivly mount-bind other filesystems into /backup/restic/
For example:

mount --bind /local /backup/restic/local
mount --bind /data /backup/restic/ldata

That I would have a "all in one backup".

What do you think of this idea?

-- 
Ullrich Horlacher              Server und Virtualisierung
Rechenzentrum TIK
Universitaet Stuttgart         E-Mail: horlacher@tik.uni-stuttgart.de
Allmandring 30a                Tel:    ++49-711-68565868
70569 Stuttgart (Germany)      WWW:    https://www.tik.uni-stuttgart.de/
REF:<20250628173308.GB847325@tik.uni-stuttgart.de>