stochasticflux

Mounting filesystems over SSH with Ubuntu

June 30th, 2006

A great adition to Linux has been the filesystem in user-space project FUSE which brings us SSHFS. One now has the ability to mount remote filesystems through ssh. Installing sshfs is easy with a simple sudo apt-get install sshfs.

First one must add their user name to the fuse group either via the gui or the command line tool adduser. (As pointed out by Casey you need to logout-login for the group changes to take effect.) Next one needs to insert the fuse module into the kernel with a

sudo modprobe fuse

This module should be appended to the end of /etc/modules inorder for it to load when the system boots.  Then it is possible to mount filesytems over ssh with a simple

sshfs username@sshserver: /media/directory

and then enter your password when prompted. This will automatically mount the users home directory. To mount a specific directory use

sshfs username@sshserver:/directory /media/directory.

Though most of us don’t want to open up a command line and go through this hassle everytime we want to mount our remote filesystem. For this I purpose the following solution. First we create a password-less login by setting up a trust realtionship with public keys. On the local computer in your home directory run

ssh-keygen -t rsa

When prompted for the location to save the file and a passphrase simply hit enter. The keys will be stored in $HOME/.ssh/id_rsa. The next step is to copy the public keys over to the remote server which has already been mounted in /mount/directory.

cat ~/.ssh/id_rsa.pub >> /media/directory/.ssh/authorized_keys
chmod 600 /media/directory/.ssh/authorized_keys

Now we can ssh into our remote box without the need for a password. The other problem one runs into with implementing a clean graphical sshfs experience is the fact that if one wants to unomunt the filesystem they can not simple right click unmount the system from the Gnome desktop icon. This is because umount requires root privlages, however fuse has a solution for this which is fusermount -u /media/directory. The following bash script can be attached to a menu or panel icon to do the simple mounting of the system and the unmounting if it is already mounted.

#!/bin/bash
if grep -q sshserver /proc/mounts
then fusermount -u /media/directory
else sshfs username@sshserver: /media/directory
fi

Don’t forget to replace sshserver, username, and directory with the appropriate values for your situation.

Entry Filed under: Ubuntu