Comment 12 for bug 1777674

Could you please download and install https://launchpad.net/ubuntu/+source/finalrd/3/+build/15227702/+files/finalrd_3_all.deb

(this is a link from https://launchpad.net/ubuntu/+source/finalrd/3/+build/15227702 )

And check if that helps with reboots? This should perform pivot-root from rootfs to initramfs, and generally improve shutdown reliability.

However, I do suspect this to be a kernel issue. If ahci is really identified as a kernel shutdown culprit, we might want to ship an executable script in /lib/systemd/system-shutdown/yank-modules.sh or somesuch which would rmmod ahci if possible.

So far I do not have any indications that it is indeed systemd holding up reboot, and not the kernel.