Re: restic backup with btrfs /

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

On Sat 2025-06-28 (19:33), Ulli Horlacher wrote:

> 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".

Meanwhile I haved implemented it and also use of (temporary) snapshots!
Instead of /backup/restic I am using /__ (just another name).

restix-backup does:

- create recursive snapshots of all rw subvolumes
- bind-mount the toplevel snapshots on /__
- run restic backup on /__
- umount everything below /__
- delete all temporary snapshots

Example (I have typed only the first line, all other lines are output): 

root@fex:~# restix-backup -s //

# btrfs_rsnapshot -w /
Create a snapshot of '/' in '/.snapshot/_'
Create a snapshot of '/test' in '/.snapshot/_/test'
Create a snapshot of '/tmp' in '/.snapshot/_/tmp'

# mount --bind /.snapshot/_ /__

# btrfs_rsnapshot -w /local
Create a snapshot of '/local' in '/local/.snapshot/_'
Create a snapshot of '/local/home' in '/local/.snapshot/_/home'
Create a snapshot of '/local/home/framstag/blubb' in '/local/.snapshot/_/home/framstag/blubb'
Create a snapshot of '/local/home/smc/test' in '/local/.snapshot/_/home/smc/test'
Create a snapshot of '/local/test' in '/local/.snapshot/_/test'
Create a snapshot of '/local/test/sv1' in '/local/.snapshot/_/test/sv1'
Create a snapshot of '/local/test/sv1/sv1_1' in '/local/.snapshot/_/test/sv1/sv1_1'
Create a snapshot of '/local/test/sv1/sv1_1/ss' in '/local/.snapshot/_/test/sv1/sv1_1/ss'
Create a snapshot of '/local/test/sv1/sv1_2' in '/local/.snapshot/_/test/sv1/sv1_2'
Create a snapshot of '/local/test/sv2' in '/local/.snapshot/_/test/sv2'
Create a snapshot of '/local/tmp/test' in '/local/.snapshot/_/tmp/test'

# mount --bind /local/.snapshot/_ /__/local

# cd /

# findattr __ > __/.chattr

# restic backup -v -e /tmp -e /backup -e .cache -e .del -e tmp/\* -e \*.tmp -H fex --tag __ __
RESTIC_ENV=/root/.restic/s3tik.env
SG_TENANT=fex
RESTIC_REPOSITORY=s3:s3.tik.uni-stuttgart.de/fex.restic

# /opt/s3tik/restic backup -v -e /tmp -e /backup -e .cache -e .del -e 'tmp/*' -e '*.tmp' -H fex --tag __ __
open repository
repository 13e662d4 opened (version 2, compression level auto)
using parent snapshot 20b48e38
load index files
[0:02] 100.00%  36 / 36 index files loaded
start scan on [__]
start backup on [__]
scan finished in 4.728s: 254436 files, 46.446 GiB

Files:           1 new,   105 changed, 254330 unmodified
Dirs:            2 new, 18860 changed,  2765 unmodified
Data Blobs:     37 new
Tree Blobs:    168 new
Added to the repository: 35.310 MiB (7.926 MiB stored)

processed 254436 files, 46.446 GiB in 0:32
snapshot 1624348b saved

# restic unlock
SG_TENANT=fex
RESTIC_REPOSITORY=s3:s3.tik.uni-stuttgart.de/fex.restic

# /opt/s3tik/restic unlock

# umount /__//local

# btrfs_rsnapshot -d /local
Delete subvolume (no-commit): '/local/.snapshot/_/tmp/test'
Delete subvolume (no-commit): '/local/.snapshot/_/test/sv2'
Delete subvolume (no-commit): '/local/.snapshot/_/test/sv1/sv1_2'
Delete subvolume (no-commit): '/local/.snapshot/_/test/sv1/sv1_1/ss'
Delete subvolume (no-commit): '/local/.snapshot/_/test/sv1/sv1_1'
Delete subvolume (no-commit): '/local/.snapshot/_/test/sv1'
Delete subvolume (no-commit): '/local/.snapshot/_/test'
Delete subvolume (no-commit): '/local/.snapshot/_/home/smc/test'
Delete subvolume (no-commit): '/local/.snapshot/_/home/framstag/blubb'
Delete subvolume (no-commit): '/local/.snapshot/_/home'
Delete subvolume (no-commit): '/local/.snapshot/_'

# umount /__//

# btrfs_rsnapshot -d /
Delete subvolume (no-commit): '/.snapshot/_/tmp'
Delete subvolume (no-commit): '/.snapshot/_/test'
Delete subvolume (no-commit): '/.snapshot/_'

# restic forget --prune --tag __ --host fex --keep-daily 7 --keep-weekly 4
SG_TENANT=fex
RESTIC_REPOSITORY=s3:s3.tik.uni-stuttgart.de/fex.restic

# /opt/s3tik/restic forget --prune --tag __ --host fex --keep-daily 7 --keep-weekly 4
Applying Policy: keep 7 daily, 4 weekly snapshots
keep 2 snapshots:
ID        Time                 Host        Tags        Reasons                 Paths  Size
------------------------------------------------------------------------------------------------
20b48e38  2025-07-07 13:53:14  fex         __          oldest daily snapshot   /__    46.446 GiB
                                                       oldest weekly snapshot
1624348b  2025-07-07 14:05:42  fex         __          daily snapshot          /__    46.446 GiB
                                                       weekly snapshot
------------------------------------------------------------------------------------------------
2 snapshots


# restic check
SG_TENANT=fex
RESTIC_REPOSITORY=s3:s3.tik.uni-stuttgart.de/fex.restic

# /opt/s3tik/restic check
using temporary cache in /tmp/root/restic-check-cache-988330367
create exclusive lock for repository
load indexes
check all packs
check snapshots, trees and blobs
[0:12] 100.00%  35 / 35 snapshots
no errors were found


-- 
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>