Can not unmount an S3 directory mounted with s3fs-fuse

Question

I have an s3fs-fuse "device" mounted at /mnt/s3. I want to unmount it so that I can remount it with the mp_umask flag so that chroot will work properly.

The command should be:

fusermount -u /mnt/s3

Unfortunately the result is:

fusermount: failed to unmount /mnt/s3: Device or resource busy

That's not helpful. Shouldn't be this hard!

Solution 1

You can use lsof to figure out which files are still open.

Solution 2

The command that worked was:

umount -l /mnt/s3

Comments

[Andrew Gaul]

This might not unmount the filesystem if one of the opens is long-lived; it is better to actually close the open files.

[Aftab Naveed]

In my case there were no open files, unmounting using that command did work for me.