SSHFS: Cannot umount / re-mount remote directory after connection is interrupted

Question

I often use sshfs to mount a remote directory to make it appear as local:

sudo sshfs -o allow_other myname@server:/remote/path /mnt/remote/

Occasionally there could be interruption to the connection so /mnt/remote will appear as empty. If I try to re-run the above command, I'd get

'/mnt/remote:' Transport endpoint is not connected'

However I'm unable to (force) unmount the directory either:

sudo umount (-f) /mnt/remote
umount: /mnt/remote: target is busy

I'm wondering what can I do to re-mount the directory without rebooting my machine?

Answer 1

sudo umount -l /mnt/remote seems to work.

Got this answer from a friend. -l stands for lazy and I wouldn't have guessed the solution by myself.

Answer 2

You should find out which process is keeping the mountpoint busy. For example this:

lsof /mnt/remote

will list those processes (there could be many).

You then end them (normal close, or kill as shutdown would do) and try to unmount again sudo fusermount -u /mnt/remote)