Comment 0 for bug 358654

I've just finished helping a German user diagnose a failed-boot issue after the system had been updated. The failure means that although udevd starts it doesn't do anything so no devices are populated.

Later, we found a forums post (also in the German language) with the same issue which shows:

udevadm trigger is not premitted while udev is unconfigured.
Gave up waiting for root device. Common problems:
-Boot args (cat /proc/cmdline)
  -Check rootdelay= (did the system wait long enough)
  -Check root= (did the system wait for the right device?)
-Missing modules (cat /proc/modules; ls /dev)
ALERT! /dev/disk/by-uuid/05d79451-0ad0-43fc-9f51-a2c98b4831f2 does not exist.
Dropping to a shell!

See: http://forum.ubuntuusers.de/topic/nach-update-bootet-laptop-nicht-mehr/

It seems that the user was prompted to restart the system before the system had been fully configured. I'm not sure how that could happen and unfortunately we have no logs to look at, but this should at least be on the radar.

The user reported he updates the system every day so in this case the difference was between 8th April and 9th April.

Discussing it on 'ubuntu-devel kees suggested the best packages to post this against since:

<kees> you could open it against both udev and linux :)
<kees> ...well both of those packages drop the "please reboot" file, so they likely both need to be fixed.

The solution is to use a live-CD to mount the system (or boot from a completely separate installation), mount the failed OS partition(s), and complete the update process:

e.g.

sudo -i

# create a target mount point
mkdir /mnt/target

# mount root
mount /dev/sda8 /mnt/target
# mount boot
mount /dev/sda9 /mnt/target/boot

# into Jaunty
chroot /mnt/target/

# update
dpkg --configure -a

# done
exit

#unmount
umount /mnt/target/boot
umount /mnt/target