# umount wren:/usr/local/bin

  The opposite of the mount command is the umount command, which is used to remove a mounted directory/folder from the local filesystem.   A filesystem can be dismounted using either the remote filesystem name or the local mount point directory on the umount command line, so to dismount the /usr/local/bin directory, enter either the remote name (see above) or the local name

   # umount /usr/local/bin

  The -a option dismounts every filesystem listed in the /etc/mtab file.   In other words, it dismounts all currently mounted filesystem.   The -f options has particular relevance to NFS because it forces the dismount, even if the remote NFS server is unresponsive.