On a debian server, I have unionfs mounted with no entry in fstab. How can I figure out the command, that was used to mount it (or which directories make up the union) ?
Edit: The above will work for unionfs, the 'original one', implemented as kernel module. As you are using the user-space alternative – unionfs-fuse, things are a bit different.
In this case try looking for unionfs-fuse command line: