A few days ago my Ubuntu installation got corrupted during what should have been an easy no worries apt-upgrade. What happened though is that during the apt-upgrade, precisely during kernel updates, my system crashed. Afterwards, I was not able to boot anymore due to lib modules missing.
So the usual was to be done, get a usb rescue stick, chroot and try to complete the upgrade. Unfortunately, the system still did not boot. During boot, my filesystem could not be decrypted. Sigh.
After stumbling around for a bit, I finally came across a helpful stackoverflow post explaining the following:
The cryptsetup modules are only added to the initramfs image “when there is a device that needs to be unlocked at initramfs stage (such as root or resume devices)” (See:
conf-hook). But this currently only works (reliably) if the root device is not in an (encrypted) LVM.
To force the cryptsetup modules to the initramfs image you have to set
This exactly described my situation, I did have an encrypted FS within an logical volume. So set the flag to yes, and was able to boot again 🙂 Note that this setting is soon to be deprecated and might not work anymore.