When LVM/RAID/etc. don't work on boot

Boot with break=premount on the kernel command line, remove both quiet and splash for sanity.

(initramfs) rm scripts/init-premount/udev
(initramfs) echo "" > /proc/sys/kernel/hotplug
(initramfs) /sbin/udevd --verbose --supress-syslog >/dev/udevd.log 2>&1 &
(initramfs) /sbin/udevtrigger

Now press ^D and let the boot continue; once it has booted, please provide the /dev/udevd.log file.