[systemd-devel] pivot_root to a tmpfs directory to properly umount root

[harald at redhat.com]

With this patch series, it is possible to umount the root device and deconstruct it.

You can copy a bash to /lib/systemd/system-shutdown/ and it will be executed at the end.
Then you can cat /proc/mounts with:

# while read line; do echo $line; done < /proc/mounts

And your root device should not be showing up.

See:
http://www.harald-hoyer.de/files/systemd-pivot.png