System administration and SSH is a topic I’ve covered before (see System Administration Toolkit: Set up remote access in UNIX through OpenSSH), but what I didn’t cover in that article was how you can use SSH as a solution for running commands remotely over one, or more, machines simultaneously. From the new article:

Use Secure Shell (SSH) to run commands on remote UNIX systems and, with some simple scripts, put together a system that enables you to manage many systems simultaneously from one machine without having to log in directly to the machines themselves. Also examine the basics of a distributed management system and some scripts and solutions using the technique.

Read: System Administration Toolkit: Distributed administration using SSH