Arch Linux

nautek

Member

Registered: 2023-06-17

Posts: 3

[solved] Cannot boot after timeshift restore (vfat unknown filesystem)

Dear all,

this is my first proper post here and I feel bad for joining since I am stuck. But I really need some help. Today I did a full pacman -Syu update but an AUR package was not working anymore, so I did a timeshift restore to the snapshot before the upgrade. I rebooted the system but it could not mount the boot folder (error: unknown filesystem VFAT) and went to emergency mode. In the emergency mode I tried to restore another timeshift snapshot but that also fails because it cannot mount the boot partition (same VFAT error).

I am on a Windows dualboot, with an VFAT boot partition, a separate BTRFS Linux home partition and I use sytemd as the bootloader. I tried my best to go through forums and help pages but nothing really helped. The common problem pointed out was different kernel versions but -uname a and pacman -Q linux produce the same version (arch 6.3.8-arch1-1) so this does not seem to be the issue?

„modinfo vfat“ gives error: module vfat not found

Sorry that I cannot paste logs since I cannot use the broken linux system. I took some photos but I can only post them here when I host them somewhere?

I would really appreciate any suggestions.

Many thanks!

Last edited by nautek (2023-06-20 12:27:44)

jonno2002

Member

Registered: 2016-11-21

Posts: 868

Re: [solved] Cannot boot after timeshift restore (vfat unknown filesystem)

i dont use systemd-boot but after a quick read of the wiki and man page id say your "esp/loader/entries/arch.conf" has the wrong entry for "root=" and its probably trying to use your efi partition as root.
if you cant change this in rescue mode then you will have to boot the arch installer and chroot in and fix it.

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 25,255

Re: [solved] Cannot boot after timeshift restore (vfat unknown filesystem)

Your kernel is not part of the snapshot if it's on /boot and if /boot is the mount point of your ESP which is VFAT so what will happen with your rollback is that the kernel on the /boot partition diverges from the kernel you are intending to boot into.

Boot into a live disk and either revert your snapshot to current or install the kernel package of the actually older kernel that's in your snapshot. (And exclude /usr/lib/modules from the snapshot logic if you don't want to get hit by this again)

nautek

Member

Registered: 2023-06-17

Posts: 3

Re: [solved] Cannot boot after timeshift restore (vfat unknown filesystem)

Thanks a lot for your input, V1del and Jonno. Using a Live Linux on a USB Stick and restoring the latest snapshot with Timeshift solved the problem. Many many thanks

I still dont yet understand how to best follow your advice on how to exclude the usr/lib/modules since I use an autosnapshot functionality but I surely do some more homework on how to use timeshift in my setup.