I need to get to recovery mode so I can run
zerofree on my root partition before shrinking the hard disk (it's a virtual machine hard disk).
When I boot to recovery mode (via grub), it mounts
/ and I can't unmount it (
target is busy). All of the stuff I find says that
/ should not be mounted when I go into recovery mode and all my searches result in pages that instruct you on how to mount it.
How do I figure out what's going on and get into recovery mode without
/ being mounted?