It will prompt "Failed to unmount /oldroot" when shutdown or reboot after installing finalrd

[binli]

systemd version the issue has been seen with

245.4-4ubuntu3.11

Used distribution

Ubuntu OS 20.04.2

Linux kernel version used (uname -a)

5.11.0-25-generic

CPU architecture issue was seen on

x86_64

Expected behaviour you didn't see

No error show up

Unexpected behaviour you saw

sd-umoun[2406]: Failed to unmount /oldroot: Device or resource busy

Steps to reproduce the problem

Install the finalrd package and reboot, then you could find these errors on shutdown or reboot.

Additional program output to the terminal or log subsystem illustrating the issue

 sd-umoun[2406]: Failed to unmount /oldroot: Device or resource busy
 sd-umoun[2407]: Failed to unmount /oldroot/dev/pts: Device or resource busy
 sd-umoun[2408]: Failed to unmount /oldroot/dev: Device or resource busy
 shutdown[1]: Failed to finalize  file systems, ignoring

[poettering]

What is "finalrd"? And if that's causing the issue, why are you not filing an issue against that?

Also, the submission form makes very clear this should only be used for issues with the two most recent systemd versions, which are 248/249 right now 245 is waaay older than that. For older stuff please contact your distro

[binli]

Thanks for your feedback.