Unable to rollback from read-only snapshot

tbt92317 · May 9, 2024, 10:18am

The most current snapshot on my system is unbootable (long story). I’m booting into a prior read-only snapshot successfully, but when attempting a snapper rollback, I’m encountering this:

➜  ~ sudo snapper -v --debug rollback
constructing ProxySnapper object
executing command
Ambit is classic.
Creating read-only snapshot of default subvolume.THROW: dbus error exception
CAUGHT: dbus error exception
Creating snapshot failed.

Can’t see any more info in journalctl, so I’m at a bit of a loss and would appreciate any pointers.

btrfs subvolume list

➜  ~ sudo btrfs subvolume list /                           
ID 256 gen 78939 top level 5 path @
ID 257 gen 78993 top level 256 path @/var
ID 258 gen 78972 top level 256 path @/usr/local
ID 259 gen 78562 top level 256 path @/srv
ID 260 gen 78977 top level 256 path @/root
ID 261 gen 78562 top level 256 path @/opt
ID 262 gen 78993 top level 256 path @/home
ID 263 gen 63305 top level 256 path @/boot/grub2/x86_64-efi
ID 264 gen 63305 top level 256 path @/boot/grub2/i386-pc
ID 265 gen 78991 top level 256 path @/.snapshots
ID 266 gen 78942 top level 265 path @/.snapshots/1/snapshot
ID 453 gen 63305 top level 257 path @/var/lib/machines
ID 742 gen 78846 top level 265 path @/.snapshots/476/snapshot
ID 743 gen 78846 top level 265 path @/.snapshots/477/snapshot
ID 744 gen 78846 top level 265 path @/.snapshots/478/snapshot
ID 745 gen 78846 top level 265 path @/.snapshots/479/snapshot
ID 774 gen 78846 top level 265 path @/.snapshots/508/snapshot
ID 775 gen 78846 top level 265 path @/.snapshots/509/snapshot
ID 787 gen 78846 top level 265 path @/.snapshots/521/snapshot
ID 788 gen 78846 top level 265 path @/.snapshots/522/snapshot
ID 789 gen 78846 top level 265 path @/.snapshots/523/snapshot
ID 790 gen 78846 top level 265 path @/.snapshots/524/snapshot
ID 791 gen 78870 top level 265 path @/.snapshots/525/snapshot
ID 792 gen 78879 top level 265 path @/.snapshots/526/snapshot
ID 793 gen 78883 top level 265 path @/.snapshots/527/snapshot
ID 794 gen 78891 top level 265 path @/.snapshots/528/snapshot
ID 795 gen 78901 top level 265 path @/.snapshots/529/snapshot
ID 796 gen 78908 top level 265 path @/.snapshots/530/snapshot

fstab

➜  ~ cat /etc/fstab                               
/dev/system/root                           /                       btrfs  defaults                      0  0
/dev/system/root                           /var                    btrfs  subvol=/@/var                 0  0
/dev/system/root                           /usr/local              btrfs  subvol=/@/usr/local           0  0
/dev/system/root                           /srv                    btrfs  subvol=/@/srv                 0  0
/dev/system/root                           /root                   btrfs  subvol=/@/root                0  0
/dev/system/root                           /opt                    btrfs  subvol=/@/opt                 0  0
/dev/system/root                           /home                   btrfs  subvol=/@/home                0  0
/dev/system/root                           /boot/grub2/x86_64-efi  btrfs  subvol=/@/boot/grub2/x86_64-efi  0  0
/dev/system/root                           /boot/grub2/i386-pc     btrfs  subvol=/@/boot/grub2/i386-pc  0  0
UUID=85C8-70B8                             /boot/efi               vfat   utf8                          0  2
/dev/system/root                           /.snapshots             btrfs  subvol=/@/.snapshots          0  0
UUID=047C84337C842212                      /mnt/x                  ntfs   umask=0000,windows_names,hide_dot_files,discard,uid=1000,gid=1000,exec  0  0
/dev/mapper/cr_system-swap                 swap                    swap   defaults                      0  0

snapper list

➜  ~ sudo snapper list              
   # | Type   | Pre # | Date                         | User | Used Space | Cleanup | Description           | Userdata     
-----+--------+-------+------------------------------+------+------------+---------+-----------------------+--------------
  0  | single |       |                              | root |            |         | current               |              
  1+ | single |       | Mo 25 Mär 2024 13:37:29 CET  | root | 151,50 MiB |         | first root filesystem |              
476  | pre    |       | Fr 03 Mai 2024 14:10:16 CEST | root | 314,51 MiB | number  | zypp(zypper)          | important=yes
477  | post   |   476 | Fr 03 Mai 2024 14:10:30 CEST | root |   5,41 MiB | number  |                       | important=yes
478  | pre    |       | Fr 03 Mai 2024 22:53:42 CEST | root |  10,98 MiB | number  | zypp(packagekitd)     | important=yes
479  | post   |   478 | Fr 03 Mai 2024 22:57:06 CEST | root | 317,75 MiB | number  |                       | important=yes
508- | pre    |       | Di 07 Mai 2024 15:47:59 CEST | root | 327,49 MiB | number  | zypp(packagekitd)     | important=no 
509  | post   |   508 | Di 07 Mai 2024 15:49:05 CEST | root |  71,69 MiB | number  |                       | important=no 
521  | pre    |       | Di 07 Mai 2024 17:45:02 CEST | root |  79,88 MiB | number  | zypp(zypper)          | important=no 
522  | post   |   521 | Di 07 Mai 2024 17:45:16 CEST | root | 640,00 KiB | number  |                       | important=no 
523  | pre    |       | Di 07 Mai 2024 18:26:23 CEST | root |   1,19 MiB | number  | zypp(packagekitd)     | important=no 
524  | post   |   523 | Di 07 Mai 2024 18:27:12 CEST | root |   1,08 MiB | number  |                       | important=no 
525  | pre    |       | Di 07 Mai 2024 21:48:49 CEST | root |   1,73 MiB | number  | before update         | important=yes
526  | post   |   525 | Di 07 Mai 2024 21:53:40 CEST | root |  96,00 KiB | number  | after update          | important=yes
527  | pre    |       | Di 07 Mai 2024 22:02:25 CEST | root |  96,00 KiB | number  | before update         | important=yes
528  | post   |   527 | Di 07 Mai 2024 22:05:48 CEST | root | 272,00 KiB | number  | after update          | important=yes
529  | pre    |       | Di 07 Mai 2024 23:00:51 CEST | root | 352,00 KiB | number  | before update         | important=yes
530  | post   |   529 | Di 07 Mai 2024 23:04:18 CEST | root |  38,18 MiB | number  | after update          | important=yes

arvidjaar · May 9, 2024, 11:17am

Upload output as root of

journalctl -b --full --no-pager

to https://paste.opensuse.org/

And show

btrfs filesystem usage -T /

tbt92317 · May 9, 2024, 12:02pm

Journalctl

btrfs filesystem usage -T /

➜  ~ sudo btrfs filesystem usage -T /                                             
Overall:
    Device size:                 201.12GiB
    Device allocated:            161.07GiB
    Device unallocated:           40.05GiB
    Device missing:                  0.00B
    Device slack:                    0.00B
    Used:                        150.68GiB
    Free (estimated):             47.31GiB      (min: 27.29GiB)
    Free (statfs, df):            47.31GiB
    Data ratio:                       1.00
    Metadata ratio:                   2.00
    Global reserve:              216.52MiB      (used: 0.00B)
    Multiple profiles:                  no

                           Data      Metadata System                              
Id Path                    single    DUP      DUP      Unallocated Total     Slack
-- ----------------------- --------- -------- -------- ----------- --------- -----
 1 /dev/mapper/system-root 155.01GiB  6.00GiB 64.00MiB    40.05GiB 201.12GiB     -
-- ----------------------- --------- -------- -------- ----------- --------- -----
   Total                   155.01GiB  3.00GiB 32.00MiB    40.05GiB 201.12GiB 0.00B

arvidjaar · May 9, 2024, 12:13pm

You could try

snapper --no-dbus ...

If anything, it may give some more information what goes wrong.

tbt92317 · May 9, 2024, 1:00pm

Sure thing.

snapper --no-dbus

➜  ~ sudo snapper --no-dbus -v --debug rollback      
[sudo] password for root: 
constructing ProxySnapper object
executing command
Snapper constructor
snapper version 0.10.7
libsnapper version 7.4.0
config_name:root root_prefix:/ disable_filters:false
loading file /etc/snapper/configs/root
key:SUBVOLUME value:/
key:FSTYPE value:btrfs
key:QGROUP value:1/0
SELinux support disabled
key:SYNC_ACL value:no
subvolume:/ filesystem:btrfs
number of ignore patterns:8
found 18 snapshots
Ambit is classic.
Creating read-only snapshot of default subvolume.THROW: open failed path://.snapshots/531 errno:2 (No such file or directory)
CAUGHT: open failed path://.snapshots/531 errno:2 (No such file or directory)
constructor SystemCmd: /usr/lib/snapper/plugins/10-sdbootutil.snapper create-snapshot-pre / btrfs 531
sout:4 serr:6
[0] fd:4 ev:0x1 [1] fd:6 ev:0x1
poll ret:2
NewLine out:true err:true
Text_Ci: NewLine:true
Text_Ci: NewLine:true
NewLine out:true err:true
Wait ret:10412
NewLine out:true err:true
Text_Ci: NewLine:true
Text_Ci: NewLine:true
NewLine out:true err:true
Wait:10412 pid:10412 stat:0 Ret:0
stopwatch 0.001591s for "/usr/lib/snapper/plugins/10-sdbootutil.snapper create-snapshot-pre / btrfs 531"
NewLine out:true err:true
NewLine out:true err:true
system() Returns:0
create snapshot failed, btrfs_util_create_snapshot_fd2() failed, errno:2 (No such file or directory)
THROW: create snapshot failed
CAUGHT: create snapshot failed
RETHROW: create snapshot failed
Snapper destructor
CAUGHT: create snapshot failed
Error (create snapshot failed).

arvidjaar · May 9, 2024, 1:04pm

Show

btrfs qgroup show /

tbt92317 · May 9, 2024, 1:22pm

btrfs qgroup show /

Qgroupid    Referenced    Exclusive   Path 
--------    ----------    ---------   ---- 
0/5           16.00KiB     16.00KiB   <toplevel>
0/256         52.00KiB     52.00KiB   @
0/257          5.00GiB      5.00GiB   @/var
0/258          2.58MiB    128.00KiB   @/usr/local
0/259         16.00KiB     16.00KiB   @/srv
0/260        162.98MiB    162.98MiB   @/root
0/261         16.00KiB     16.00KiB   @/opt
0/262        123.98GiB    123.93GiB   @/home
0/263         16.00KiB     16.00KiB   @/boot/grub2/x86_64-efi
0/264         16.00KiB     16.00KiB   @/boot/grub2/i386-pc
0/265        108.00KiB    108.00KiB   @/.snapshots
0/266         14.97GiB    151.50MiB   @/.snapshots/1/snapshot
0/453         16.00KiB     16.00KiB   @/var/lib/machines
0/706            0.00B        0.00B   <stale>
0/707            0.00B        0.00B   <stale>
0/722            0.00B        0.00B   <stale>
0/723            0.00B        0.00B   <stale>
0/740            0.00B        0.00B   <stale>
0/741            0.00B        0.00B   <stale>
0/742         14.85GiB    314.51MiB   @/.snapshots/476/snapshot
0/743         14.63GiB      5.41MiB   @/.snapshots/477/snapshot
0/744         14.63GiB     10.98MiB   @/.snapshots/478/snapshot
0/745         14.62GiB    317.75MiB   @/.snapshots/479/snapshot
0/766            0.00B        0.00B   <stale>
0/769            0.00B        0.00B   <stale>
0/770            0.00B        0.00B   <stale>
0/771            0.00B        0.00B   <stale>
0/772            0.00B        0.00B   <stale>
0/773            0.00B        0.00B   <stale>
0/774         14.86GiB    327.49MiB   @/.snapshots/508/snapshot
0/775         14.82GiB     71.69MiB   @/.snapshots/509/snapshot
0/776            0.00B        0.00B   <stale>
0/777            0.00B        0.00B   <stale>
0/778            0.00B        0.00B   <stale>
0/779            0.00B        0.00B   <stale>
0/780            0.00B        0.00B   <stale>
0/781            0.00B        0.00B   <stale>
0/782            0.00B        0.00B   <stale>
0/783            0.00B        0.00B   <stale>
0/784            0.00B        0.00B   <stale>
0/785            0.00B        0.00B   <stale>
0/786            0.00B        0.00B   <stale>
0/787         14.84GiB     79.88MiB   @/.snapshots/521/snapshot
0/788         14.83GiB    640.00KiB   @/.snapshots/522/snapshot
0/789         14.83GiB      1.19MiB   @/.snapshots/523/snapshot
0/790         14.97GiB      1.08MiB   @/.snapshots/524/snapshot
0/791         14.97GiB      1.73MiB   @/.snapshots/525/snapshot
0/792         14.76GiB     96.00KiB   @/.snapshots/526/snapshot
0/793         14.76GiB     96.00KiB   @/.snapshots/527/snapshot
0/794         14.76GiB    272.00KiB   @/.snapshots/528/snapshot
0/795         14.76GiB    352.00KiB   @/.snapshots/529/snapshot
0/796         14.86GiB     38.18MiB   @/.snapshots/530/snapshot

arvidjaar · May 9, 2024, 1:36pm

And

snapper get-config

tbt92317 · May 9, 2024, 1:39pm

snapper get-config

Key                    | Value
-----------------------+------
ALLOW_GROUPS           |      
ALLOW_USERS            |      
BACKGROUND_COMPARISON  | yes  
EMPTY_PRE_POST_CLEANUP | yes  
EMPTY_PRE_POST_MIN_AGE | 1800 
FREE_LIMIT             | 0.2  
FSTYPE                 | btrfs
NUMBER_CLEANUP         | yes  
NUMBER_LIMIT           | 2-10 
NUMBER_LIMIT_IMPORTANT | 4-10 
NUMBER_MIN_AGE         | 1800 
QGROUP                 | 1/0  
SPACE_LIMIT            | 0.5  
SUBVOLUME              | /    
SYNC_ACL               | no   
TIMELINE_CLEANUP       | yes  
TIMELINE_CREATE        | no   
TIMELINE_LIMIT_DAILY   | 10   
TIMELINE_LIMIT_HOURLY  | 10   
TIMELINE_LIMIT_MONTHLY | 10   
TIMELINE_LIMIT_WEEKLY  | 0    
TIMELINE_LIMIT_YEARLY  | 10   
TIMELINE_MIN_AGE       | 1800

arvidjaar · May 9, 2024, 1:44pm

Well, summary qroup is missing. You can either remove it from snapper config or create it on your root filesystem

btrfs qgroup create 1/0 /

It helps in estimating how much space snapshots consume in total.

The existing snapshots will be missing (they can be added), but future snapshots will be included in the summary.

tbt92317 · May 9, 2024, 1:54pm

That did the trick. You’re a star. Very much appreciate you taking the time, thank you.

system · May 17, 2024, 12:30am

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