Can't rollback via snapper (Loading Linux xxx-default ...)

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1

I upgraded Tumbleweed and ran into problems, so I tried to rollback via Grub menu. All expected snapshots were present. However, after selecting any of the available snapshots the boot process stopped with a black screen and only this message …

Loading Linux 6.11.8-1-default ...

This is what I get from “snapper list” on the command line:

    # │ Type   │ Pre # │ Date                     │ User │ Used Space │ Cleanup │ Description           │ Userdata
──────┼────────┼───────┼──────────────────────────┼──────┼────────────┼─────────┼───────────────────────┼──────────────
   0  │ single │       │                          │ root │            │         │ current               │
 850* │ single │       │ Wed Jun 21 08:52:11 2023 │ root │   4.44 MiB │         │ writable copy of #844 │
1143  │ pre    │       │ Sat Oct 26 15:42:44 2024 │ root │ 218.93 MiB │ number  │ zypp(zypper)          │ important=yes
1144  │ post   │  1143 │ Sat Oct 26 15:42:59 2024 │ root │ 592.00 KiB │ number  │                       │ important=yes
1145  │ pre    │       │ Tue Nov 12 10:07:56 2024 │ root │  12.09 MiB │ number  │ zypp(zypper)          │ important=yes
1146  │ post   │  1145 │ Tue Nov 12 10:12:27 2024 │ root │   1.22 MiB │ number  │                       │ important=yes
1147  │ pre    │       │ Tue Nov 12 10:17:15 2024 │ root │ 272.00 KiB │ number  │ zypp(zypper)          │ important=yes
1148  │ post   │  1147 │ Tue Nov 12 10:17:31 2024 │ root │   1.08 MiB │ number  │                       │ important=yes
1149  │ pre    │       │ Sun Nov 17 11:23:24 2024 │ root │  11.97 MiB │ number  │ zypp(zypper)          │ important=yes
1150  │ post   │  1149 │ Sun Nov 17 11:27:35 2024 │ root │   1.38 MiB │ number  │                       │ important=yes
1151  │ pre    │       │ Sun Nov 17 15:33:45 2024 │ root │ 384.00 KiB │ number  │ zypp(zypper)          │ important=yes
1152  │ post   │  1151 │ Sun Nov 17 15:34:02 2024 │ root │ 928.00 KiB │ number  │                       │ important=yes

I have no idea for how long rolling back fails 'cause I have to use it quite seldom. ATM I don’t know how to investigate any further. Any help appreciated.

2

Which problems?

The next message should be about loading initrd. If it never appears, it sounds like grub fails (loops?) reading btrfs. Which may indicate filesystem issues.

Can you still boot the current snapshot?

3

I ran into some problems with the docker network.

Yes, the system boots as usual. I consider this the current snapshot.

4

Can you access vmlinuz and initrd in the snapshot that fails to boot (e.g. try computing md5sum to force full read)? Anything suspicious in dmesg output after you did it?

5

I tried a few snapshots. Everything is accessible and md5 is calculated with dmesg completely quite.

6

@arvidjaar I just double checked that vmlinuz and initrd are present and readable without any errors. I am wondering if there is any chance to get an error message at this level of the boot process.

7

Fixed the issue via rebuilding grub:

grub2-mkconfig -o /boot/grub2/grub.cfg

Pretty strange from my (still non-expert) point of view on linux. :slight_smile:
Thanks for the help.

8

Which issues with docker network did you have? I also suddenly have an issue where container networking does not work for most containers (but does for some!) - connections just time out, but ping succeeds.

Have you found a solution? Did rolling back solve this for you? I am scrambling to try and find what exactly broke, and how to work around or fix it.

9

Booting from a zypper-pre snapshot of Tue 19 Nov 2024 23:16:34 CET, docker container networking still works. I will boot one snapshot after the other to find the breaking point.