Re: using snapshot for backup: best practise?

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

On Thu 2025-06-26 (13:43), Ulli Horlacher wrote:

> Using snapshots seems a better idea for backups :-)
> 
> But snapshots do not include subvolumes.
> 
> When I run the command:
> 
> btrfs subvolume snapshot / /.snapshot/_
> 
> the snapshot will contain only the root subvolume.

Mewanwhile I have written some (more) tools to handle nested subvolumes
and snapshots.

Example:

root@fex:~# btrfs_list /local/test
ACCESS-MODE SUBVOLUME <- SNAPSHOT-PARENT
rw /local/test
rw /local/test/sv1
rw /local/test/sv1/sv1_1
rw /local/test/sv1/sv1_1/ss <- /local/test/sv1/sv1_1
rw /local/test/sv1/sv1_2
rw /local/test/sv2

root@fex:~# btrfs_rsnapshot /local/test
Create a snapshot of '/local/test' in '/local/test/.snapshot/test'
Create a snapshot of '/local/test/sv1' in '/local/test/.snapshot/test/sv1'
Create a snapshot of '/local/test/sv1/sv1_1' in '/local/test/.snapshot/test/sv1/sv1_1'
Create a snapshot of '/local/test/sv1/sv1_1/ss' in '/local/test/.snapshot/test/sv1/sv1_1/ss'
Create a snapshot of '/local/test/sv1/sv1_2' in '/local/test/.snapshot/test/sv1/sv1_2'
Create a snapshot of '/local/test/sv2' in '/local/test/.snapshot/test/sv2'

root@fex:~# btrfs_list /local/test
ACCESS-MODE SUBVOLUME <- SNAPSHOT-PARENT
rw /local/test
ro /local/test/.snapshot/test <- /local/test
ro /local/test/.snapshot/test/sv1 <- /local/test/sv1
ro /local/test/.snapshot/test/sv1/sv1_1 <- /local/test/sv1/sv1_1
ro /local/test/.snapshot/test/sv1/sv1_1/ss <- /local/test/sv1/sv1_1/ss
ro /local/test/.snapshot/test/sv1/sv1_2 <- /local/test/sv1/sv1_2
ro /local/test/.snapshot/test/sv2 <- /local/test/sv2
rw /local/test/sv1
rw /local/test/sv1/sv1_1
rw /local/test/sv1/sv1_1/ss <- /local/test/sv1/sv1_1
rw /local/test/sv1/sv1_2
rw /local/test/sv2

root@fex:~# btrfs_rsnapshot -d /local/test
Delete subvolume (no-commit): '/local/test/.snapshot/test/sv2'
Delete subvolume (no-commit): '/local/test/.snapshot/test/sv1/sv1_2'
Delete subvolume (no-commit): '/local/test/.snapshot/test/sv1/sv1_1/ss'
Delete subvolume (no-commit): '/local/test/.snapshot/test/sv1/sv1_1'
Delete subvolume (no-commit): '/local/test/.snapshot/test/sv1'
Delete subvolume (no-commit): '/local/test/.snapshot/test'

root@fex:~# btrfs_list /local/test
ACCESS-MODE SUBVOLUME <- SNAPSHOT-PARENT
rw /local/test
rw /local/test/sv1
rw /local/test/sv1/sv1_1
rw /local/test/sv1/sv1_1/ss <- /local/test/sv1/sv1_1
rw /local/test/sv1/sv1_2
rw /local/test/sv2


-- 
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:<20250626114345.GA615977@tik.uni-stuttgart.de>