yabsnap snapshots empty

gabx · 2025-07-22 12:56:43

I have been running yabsnap since a while and didn't encounter any issue. Here is part of one of my config file:

$ cat /etc/yabsnap/configs/back-home.conf
# All configurations must be under the [DEFAULT] section.
[DEFAULT]

# Source, must be a btrfs mount.
# For example, `source = /` or `source = /home`.
source = /home

# Destination including directory and prefix where the snapshots will be stored.
# For example, `dest_prefix = /.snapshots/@root-` will result in snapshots like
# "/.snapshots/@root-20230315120000".
# Time in the format YYYYMMDDhhmmss will be added to the prefix while creating snaps.
dest_prefix = /.snapshots/back-home-

# Only one snap can be made within this interval.
# The intervals are counted from 1970 Jan 1, 12:00 AM UTC.
trigger_interval = 1 hour

# How much minimum time must pass before a snap can be cleaned up.
min_keep_secs = 1800
....

The last two saved snapshot are in the /.snapshots and the systemd timer service file is OK.
Having a look inside the snqapshot folder, I just realised my user folders are empty !!

gabx@magnolia ➤➤ ~ % sudo ls -al /.snapshots/back-home-20250721185614/gabx
[sudo] password for gabx:
total 0
drwx------ 1 root root  0 Jun 16 22:37 .
drwxr-xr-x 1 root root 80 Jun 16 22:50 ..
gabx@magnolia ➤➤ ~ % sudo ls -al /.snapshots/back-home-20250721185614/gabx.homedir
total 0
drwxr-xr-x 1 root root  0 Jul 22 14:55 .
drwxr-xr-x 1 root root 80 Jun 16 22:50 ..

How can I debug this issue and fix it?
Thank you for help

seth · 2025-07-22 13:15:08

Both paths are only writable by the root and esp. not gabx?
=> fix their ownership

gabx · 2025-07-22 14:18:18

% sudo chwon -R gabx:wheel /.snapshots
chown: changing ownership of '/.snapshots/back-root-20250721020024/usr/lib/pkgconfig/geocode-glib-2.0.pc': Read-only file system
..... and so on
% cat /etc/fstab
UUID=6ca0f63e-7327-444e-af89-ac82d08fda59	/.snapshots		btrfs		rw,noatime,ssd,discard,space_cache=v2,compress=zstd,subvol=/@snapshots	0 0

Why is the filesystem read-only?

WorMzy · 2025-07-22 14:25:49

Mod note: moving to AUR Issues.

seth · 2025-07-22 14:41:49

mount | grep snap

but you'll have to look at your journal to see why it was (re)mounted read-only (typically for FS corruptions)

gabx · 2025-07-22 15:08:06

mount | grep snap
/var/lib/snapd/snaps/bare_5.snap on /var/lib/snapd/snap/bare/5 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide,x-gvfs-hide)
/var/lib/snapd/snaps/gnome-42-2204_202.snap on /var/lib/snapd/snap/gnome-42-2204/202 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide,x-gvfs-hide)
/var/lib/snapd/snaps/core22_1748.snap on /var/lib/snapd/snap/core22/1748 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide,x-gvfs-hide)
/var/lib/snapd/snaps/gtk-common-themes_1535.snap on /var/lib/snapd/snap/gtk-common-themes/1535 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide,x-gvfs-hide)
/var/lib/snapd/snaps/pieces-for-developers_81.snap on /var/lib/snapd/snap/pieces-for-developers/81 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide,x-gvfs-hide)
/var/lib/snapd/snaps/pieces-for-developers_82.snap on /var/lib/snapd/snap/pieces-for-developers/82 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide,x-gvfs-hide)
/var/lib/snapd/snaps/pieces-os_84.snap on /var/lib/snapd/snap/pieces-os/84 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide,x-gvfs-hide)
/var/lib/snapd/snaps/pieces-os_85.snap on /var/lib/snapd/snap/pieces-os/85 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide,x-gvfs-hide)
/var/lib/snapd/snaps/snapd_23771.snap on /var/lib/snapd/snap/snapd/23771 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide,x-gvfs-hide)
/var/lib/snapd/snaps/snapd_23545.snap on /var/lib/snapd/snap/snapd/23545 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide,x-gvfs-hide)
/dev/nvme0n1p2 on /mnt type btrfs (rw,relatime,ssd,discard,space_cache=v2,subvolid=283,subvol=/@snapshots)

I have tried to umount the subvol and the mount it rw on /mnt

# mount -t btrfs -o subvol=@snapshots,rw /dev/nvme0n1p2 /mnt
# mount | grep /mnt
/dev/nvme0n1p2 on /mnt type btrfs (rw,relatime,ssd,discard,space_cache=v2,subvolid=283,subvol=/@snapshots) <--- I can see it is rw
# chown -R gabx:wheel /mnt
chown: changing ownership of '/mnt/back-root-20250721020024/usr/share/doc/gio-2.0/property.FileMonitor.rate-limit.html': Read-only file system
...and so on

I don't see why the subvol is not mounted rw

seth · 2025-07-22 15:13:56

https://markandruth.co.uk/2016/12/29/ma … t-writable ?

gabx · 2025-07-22 16:43:22

I ran the suggested command against the snapshot directory:

# btrfs property set -ts /.snapshots/ ro false
# touch /.snapshots/test
# ls -al /.snapshots
...
-rw-r--r-- 1 root root            0 Jul 22 18:36 test  <---- i can write the directory
# chown -R gabx:gabx /.snapshots/
chown: changing ownership of '/.snapshots/back-root-20250721020024/usr/share/help/ca/gnome-text-editor/media/org.gnome.TextEditor.svg': Read-only file system
... and so on

I still can't change owner of my directories inside the snapshot directoty.
As long as the /.snapshots subvolume is a read-only filesystem, I can't see how yabsnap can write snapshots inside.

Last edited by gabx (2025-07-22 17:50:48)

seth · 2025-07-22 18:02:59

findmnt -T '/.snapshots/back-root-20250721020024/usr/share/help/ca/gnome-text-editor/media/org.gnome.TextEditor.svg'

gabx · 2025-07-23 13:20:37

% findmnt -T '/.snapshots/back-root-20250721020024/usr/share/help/ca/gnome-text-editor/media/org.gnome.TextEditor.svg'
TARGET      SOURCE                      FSTYPE OPTIONS
/.snapshots /dev/nvme0n1p2[/@snapshots] btrfs  rw,noatime,ssd,discard,space_cache=v2,subvolid=283,subvol=/@snapshots

gabx · 2025-07-23 22:56:21

When running manually yabsnap, I realized two of my three configs are working.

# yabsnap --sync internal-cronrun
# ls -al /.snapshots
.....
drwxr-xr-x 1 root root           80 Jun 16 22:50 back-home-20250723181631 <---- each home subdirectories are empty
....
drwxrwxr-x 1 gabx wheel         306 May 27 01:18 back-development-20250724004950 <--- all folders are correctly copied
....
drwxr-xr-x 1 root root          208 May 21 23:56 back-root-20250724004950 <--- all folders are correctly copied

So, snapshoting /home folders fails, when snapshots of root and /development partitions are correctly snapshoted.
No idea why snapshots of /home folders are broken.

Maybe a hint.

# btrfs check --readonly --progress --force /dev/nvme0n1p2
--- a lot of errors like the one right below
root 761 inode 16529 errors 2001, no inode item, link count wrong
	unresolved ref dir 474 index 112 namelen 23 name variables.env.fake.json filetype 1 errors 4, no inode ref
....
[4/7] checking fs roots                        (0:00:02 elapsed, 2014 items checked)
ERROR: errors found in fs roots

Can this be the root of my issues?

Last edited by gabx (2025-07-23 23:09:26)

seth · 2025-07-24 11:52:37

"Can be" - does it go away if you scrub the partition?

GerBra · 2025-07-24 12:41:34

gabx wrote:

No idea why snapshots of /home folders are broken.

Maybe post the output from

ls -lda /home/gabx*
btrfs subvolume list / | grep -v snapshots
findmnt --real

//Edit: Look also if in your last root-snapshot (back-root) the /home folder is empty. It should be empty.

Last edited by GerBra (2025-07-24 12:48:08)

Arch Linux

#1 2025-07-22 12:56:43

yabsnap snapshots empty

#2 2025-07-22 13:15:08

Re: yabsnap snapshots empty

#3 2025-07-22 14:18:18

Re: yabsnap snapshots empty

#4 2025-07-22 14:25:49

Re: yabsnap snapshots empty

#5 2025-07-22 14:41:49

Re: yabsnap snapshots empty

#6 2025-07-22 15:08:06

Re: yabsnap snapshots empty

#7 2025-07-22 15:13:56

Re: yabsnap snapshots empty

#8 2025-07-22 16:43:22

Re: yabsnap snapshots empty

#9 2025-07-22 18:02:59

Re: yabsnap snapshots empty

#10 2025-07-23 13:20:37

Re: yabsnap snapshots empty

#11 2025-07-23 22:56:21

Re: yabsnap snapshots empty

#12 2025-07-24 11:52:37

Re: yabsnap snapshots empty

#13 2025-07-24 12:41:34

Re: yabsnap snapshots empty

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