/dev/mapper/vg00-root does not exist - Advanced

In some cases, during a failed upgrade for Ubuntu's Kernel, there is a bug if the machine is running on mdraid.

This is documented on the Ubuntu Launchpad since 2007: https://bugs.launchpad.net/ubuntu/+source/lvm2/+bug/147216

As a way around this, if you're seeing that your OS is failing to boot with the error stating the /dev/mapper/xx-root does not exist, you are able to use the following examples to manually scan for the VolGroup, and then mount the root, and boot into it.

From within BusyBox on a failed boot run:

/sbin/lvm vgscan

/sbin/lvm vgchange -a y

mount /dev/mapper/vg00-root /root

exit

Then, once you are back within the Operating System, you will then be able to resolve the issue with the /lib/udev/rules.d/85-lvm2.rules file by changing the following:

SUBSYSTEM=="block", ACTION=="add|change", ENV{ID_FS_TYPE}=="lvm*|LVM*", \

RUN+="watershed sh -c '/sbin/lvm vgscan; /sbin/lvm vgchange -a y'"

SUBSYSTEM=="block", ACTION=="add|change", \

RUN+="watershed sh -c '/sbin/lvm vgscan; /sbin/lvm vgchange -a y'"

Then issue an update to the initramfs by running:

update-initramfs -u

On next boot, all should be working as intended.