Comment 22 for bug 1611277

/scripts/init-top/udev: line 14: can't create /sys/kernel/uevent-helper: Permission denied.

Gave up waiting for root device. Common problems:
- Boot args (cat /proc/cmdline)
- Check root delay= (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/mapper/ubuntu--vg-root does not exist. Dropping to a shell.
BusyBox v1.12.1 (Ubuntu 1:1.21.0-iubuntu1) built-in shell (ash) Enter 'help'
for a list a built-in commands

(initramfs)