ECE497 Tips and Tricks

Some useful tips and tricks for Linux and the Beagleboard.

Suspending ssh
Most programs can be suspended by typing ^z (Ctrl-z). If you have an ssh connection to another machine you can suspend it by entering ~^z. You can resume the connection by entering fg.

ssh and X-windows
When using ssh between to X-windows systems try

host$ ssh -CY root@beagle The -Y set the DISPLAY variable on the remote machine so you can open windows from the beagle on your host machine.

The -C compressed the data over the link. Good for slow connections.

Authorizing ssh
ssh and sftp can be set up for automatic authorization so you don't have to enter your password when using these commands. Here's how to do it:

host $ ssh-keygen host $ cd ~/.ssh host $ sftp Beagle put id_rsa.pub exit host $ ssh Beagle The first command creates an authorization key and places it in your .ssh directory. Remember the pass phrase you enter here. You'll use it below. The next two commands copy that key to your Beagle. The last command connects to your Beagle. beagle $ mkdir ~/.ssh beagle $ cd ~/.ssh beagle $ mv ../id_rsa.pub. beagle $ cp id_rsa.pub authorized_keys beagle $ exit Here we create a .ssh directory and copy the public key into it. The authorized_keys folder contains a list of all the machines that are authorized to connect to your Beagle without a password. host $ ssh Beagle This time you should see a window pop up. Enter your pass phrase from above. You should be logged into your Beagle. Log out and log in again. This time you should get access without having to enter your pass phrase.
 * On your host computer run
 * On your Beagle run
 * Back on the host computer:

Here is move information on ssh authorization.

Mounting dfs/afs
You can set up your Linux box to directly mount your afs and dfs files. The Rose-Hulman Linux Users' Group has a nice page with the details.

After installing  I added the following to my   file: sshfs#username@dfs.Rose-hulman.edu:/MyDocs/username /home/username/MyDocs fuse user,noauto,uid=1000,gid=1000 0 0 sshfs#username@dfs.rose-hulman.edu:/Users/Y/username /home/username/dfs-home fuse user,noauto,uid=1000,gid=1000 0 0 sshfs#username@afs.rose-hulman.edu: /home/username/afs-home fuse user,noauto,uid=1000,gid=1000 0 0 You'll have to replace  with your login name. Then create the mount points: cd ~ mkdir MyDocs mkdir dfs-home mkdir afs-home Now you can mount your files by using: cd ~ mount dfs-home cd dfs-home ls You should now see your dfs files. You can unmount using: cd ~ sudo umount dfs-home