As an administrator of cluster system, I have to repeat same work on each node occasionally or very often. If cluster have some of useful software installed, specifically such as management tools or administration GUI or something, job can be done nicely and elegantly. Otherwise, it's disaster. Just imagine, typing bunch of same commands over and over again in each node.
Well, there is a life saver for these under budgeted cluster system administrator.
It is 'clusterssh'.
Few days ago, I had a job assigned and it was installing a new Matlab 2008a on 8 linux machines. It is not a cluster system though, but, what I have to do is basically install Matlab 2008a 8 times, which means I have to login each node and initiate installation procedure and type all the parameters in each step of installation process again and again.
I used 'clusterssh' instead of normal ssh and I saved a lot of time and typing same thing over and over.
It's never been easier. Just type this command in your xterm;
$cssh root@machine1 root@machine2 root@machine3 root@machine4 root@machine5
then, it magically fires up 5 xterm windows concurrently and one small 'command window'. Then, click that command window to put cursor focus on it, and type any command. Now real magic starts.
For example, if you type 'ls', then you will see that command is sent to each node, ran and showed the result.
It's kind like 'one shot, kills multiple birds'
So, what I did to install Matlab 2008a on 8 Linux machines was simply that;
(1) put Matlab dvd on machine 1
(2) export dvd through NFS
(3) cssh to 7 machines
(4) mount it using NFS
(5) go through Matlab installation only once
(6) Boom! It's done.