Arch Linux

tridra

Member

Registered: 2024-11-03

Posts: 17

[SOLVED] System can't mount /boot after switching BTRFS snapshot

My system is Gnome/systemd-boot. The other day I installed Plasma taking a BTRFS snapshot of my system before installing it. Today I reverted to the snapshot that I made before installing Plasma and my system couldn't boot. Or rather it does boot but it gets stuck when it has to mount the /boot partition and it offers me to login as root from the emergency console, which I did. This is what the log says:

Apr 10 21:28:17 arch mount[622]: mount: /boot: unknown filesystem type 'vfat'.
Apr 10 21:28:17 arch mount[622]:        dmesg(1) may have more information after failed mount system call.
Apr 10 21:28:17 arch systemd[1]: boot.mount: Mount process exited, code=exited, status=32/n/a
░░ Subject: Unit process exited
░░ Defined-By: systemd
░░ Support: https://lists.freedesktop.org/mailman/listinfo/systemd-devel
░░ 
░░ An n/a= process belonging to unit boot.mount has exited.
░░ 
░░ The process' exit code is 'exited' and its exit status is 32.
Apr 10 21:28:17 arch systemd[1]: boot.mount: Failed with result 'exit-code'.
░░ Subject: Unit failed
░░ Defined-By: systemd
░░ Support: https://lists.freedesktop.org/mailman/listinfo/systemd-devel
░░ 
░░ The unit boot.mount has entered the 'failed' state with result 'exit-code'.
Apr 10 21:28:17 arch systemd[1]: Failed to mount /boot.
░░ Subject: A start job for unit boot.mount has failed
░░ Defined-By: systemd
░░ Support: https://lists.freedesktop.org/mailman/listinfo/systemd-devel
░░ 
░░ A start job for unit boot.mount has finished with a failure.
░░ 
░░ The job identifier is 381 and the job result is failed.
Apr 10 21:28:17 arch systemd[1]: Dependency failed for Local File Systems.
░░ Subject: A start job for unit local-fs.target has failed
░░ Defined-By: systemd
░░ Support: https://lists.freedesktop.org/mailman/listinfo/systemd-devel
░░ 
░░ A start job for unit local-fs.target has finished with a failure.
░░ 
░░ The job identifier is 374 and the job result is dependency.
Apr 10 21:28:17 arch systemd[1]: local-fs.target: Job local-fs.target/start failed with result 'dependency'.
Apr 10 21:28:17 arch systemd[1]: local-fs.target: Triggering OnFailure= dependencies.
Apr 10 21:28:17 arch systemd[1]: modprobe@configfs.service: Deactivated successfully.

At the moment I'm able to use the system by using a snapshot that I took before reverting my system, so post-Plasma installation, but I'm not able to use a snapshot taken before installing Plasma.

How can I fix this?

Last edited by tridra (2025-04-10 23:51:17)

tridra

Member

Registered: 2024-11-03

Posts: 17

Re: [SOLVED] System can't mount /boot after switching BTRFS snapshot

Eventually solved it by chrooting into the system rebuilding the initramfs.

Scimmia

Fellow

Registered: 2012-09-01

Posts: 13,725

Re: [SOLVED] System can't mount /boot after switching BTRFS snapshot

When you reverted, you reverted the modules for the kernel, but not the kernel itself which isn't on BTRFS. This mismatch was your problem.

tridra

Member

Registered: 2024-11-03

Posts: 17

Re: [SOLVED] System can't mount /boot after switching BTRFS snapshot

I'm starting to think that older snapshots might be useless if I don't address that. Could backing up the initramfs image be a solution or are there better ways to do it?