How To Cleanly Unmount "Fully Encrypted" LUKS/LVM

(Not sure if this belongs here)


 I've been googling and asking but I can't seem to find a solution out there.  I've noted that with LUKS/LVM "fully encrypted" setup, the root FS can't be cleanly unmounted.  Obviously this is because it's in use and it's on top of LVM inside a LUKS container.  I was wondering if there's a way to use busybox and/or kexec to move the root filesystem to an initrd/initramfs or some other virtual / ram-based root filesystem with just enough binaries to be able to cleanly unmount root, shut off LVM, and close LUKS.  Does anyone happen to know of a solution?


As best I can tell, mine is being cleanly unmounted. However, the encryption is not being cleanly shut down.

I’m not sure the latter is important. When I next boot, the root and home partitions are always showing clean - except when there was a forced power off due to some problem.

Wouldn’t a kexec still give the same problem. Namely, the system has to shutdown for kexec, so that the file systems are clean.

Systemd is not emitting as much output, so I can’t see all that happens. I get a message about crypt shutdown failing, but the file systems themselves seem to be unmounted.