Arch Linux

Ride Garcher

Member

Registered: 2023-09-30

Posts: 54

Arch won't boot after update: missing UUID and emergency mode

After a normal shutdown, my Arch system no longer boots and drops into emergency mode.

At boot, I first see this line:

/dev/sdb2: clean, 880362/15613952 files, 31250996/62411172 blocks

Normally, after this the system would boot as expected. But now I have to wait for a while, and then the error messages about the missing UUID appear.

Last time everything worked fine. I had updated my system with paru (pacman + AUR). I rebooted, and it worked,  and played Borderlands 2 without any issue.  tried to install the linux-tkg-pds kernel (which failed, but didn't break anything). Upon reboot, I got this:

[ TIME ] Timed out waiting for device /dev/disk/by-uuid/550aa2f7-aa04-4efb-9414-a3e6b6177994.
[DEPEND] Dependency failed for /mnt/mwoo.
[DEPEND] Dependency failed for Local File Systems.
[DEPEND] Dependency failed for File System Check on /dev/disk/by-uuid/550aa2f7-aa04-4efb-9414-a3e6b6177994.

Inside the emergency shell, internet doesn’t work:

# pacman -Syu
error: failed retrieving file 'core.db' ... Could not resolve host
# ping [url=http://www.google.com]www.google.com[/url]
Temporary failure in name resolution

I checked /etc/fstab and found this line:

UUID=550aa2f7-aa04-4efb-9414-a3e6b6177994 /mnt/mwoo ext4 defaults 0 2

That UUID no longer exists (confirmed with blkid). I didn't remove or change any drives.

Important note: I had this exact same issue months ago and fixed it by booting into an Arch install USB, chrooting, and running a full system update. That worked back then.

Should I try that again, or is there a better long-term fix? Why does this keep happening?

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Jr. Web developer

espresso

Member

From: Pale Blue Dot, US

Registered: 2023-05-15

Posts: 62

Re: Arch won't boot after update: missing UUID and emergency mode

I would be a bit shocked to find an entry in fstab I did not put there myself.. genfstab step in Installation Guide could pull in such an entry but we're instructed to edit any errors..

So to rectify, just comment/delete the entry.

Or, as may be useful, modify its https://man.archlinux.org/man/systemd.mount.5 option(s). 'noauto' to prevent automounting, 'nofail' to make it wanted but not required to reach filesystem target, and such.

Last edited by espresso (Yesterday 05:58:03)