Came here to suggest this. pivot_root has the advantage that it can remount the existing root. It's essentially meant for going from an initramfs using linuxrc

Came here to suggest this. pivot_root has the advantage that it can remount the existing root. It's essentially meant for going from an initramfs using linuxrc to boot to a full-on init in the other root filesystem. If things are horribly broken you could use a shell or some other process as init.