Arch Linux

adamsonj

Member

Registered: 2011-11-10

Posts: 3

[SOLVED] ERROR: Can't find root device /dev/disk/by-uuid/...

Yesterday I upgraded my Lenovo X100e

# pacman -Syu

and rebooted.  Upon reboot, I received the error

ERROR: Cannot find root device '/dev/disk/by-uuid/[...]'

just after kernel decompression. I got dropped into the recovery shell
and could not boot.

The problem persisted despite using different root device names (e.g. /dev/sda3, the actual root device).  After reading the instructions at https://wiki.archlinux.org/index.php/Chroot I used a core installation image (on a usb stick) to boot the machine, then chrooted into my installation.  I ran mkinitcpio and found that the udev hook was missing, i.e. not in /lib/initcpio/hooks.  Nor was there a file called 'udev' in /lib/initcpio/install.

I copied these files from a friend's installation and then re-ran mkinitcpio:

# mkinitcpio -p linux

I was able to reboot successfully after that.

The weird thing: I don't know how the udev hook script was deleted from /lib/initcpio/hooks.

If someone else runs into this problem: try to run mkinitcpio (e.g. by using the chroot), and check for this problem.  I think the problem was that the root device could not be found because the udev hook had not run, and therefore /dev was unpopulated.

jumzi

Member

Registered: 2009-02-20

Posts: 69

Re: [SOLVED] ERROR: Can't find root device /dev/disk/by-uuid/...

I had the same problem, thanks for the info.

I had to reinstall udev though when i chrooted in via a chakra live cd to get mkinitcpio to wanna create a new initram that works.

count-corrupt

Member

From: Germany

Registered: 2009-02-01

Posts: 112

Re: [SOLVED] ERROR: Can't find root device /dev/disk/by-uuid/...

Betwen udev-181-2 and udev-181-5, the hooks have moved from /lib/initcpio to /usr/lib/initcpio. But mkinitcpio -L should still list them.

I have a similar problem since the last update. The kernel doesn't seem to load my raid driver anymore. Upon boot it throws some cryptic udev messages at me and then crashes. Haven't found out what that is about yet.