Console Server

Gregory Bond

$FreeBSD: doc/en_US.ISO8859-1/articles/console-server/article.sgml,v 1.23 2006/08/29 07:38:22 blackend Exp $

Legal Notice

This document describes how you can use FreeBSD to set up a “console server”. A console server is a machine that you can use to monitor the consoles of many other machines, instead of a bunch of serial terminals.


Table of Contents
1 The Problem
2 Possible Solutions
3 Our Solution
4 Setting Up The Server
5 Cabling
6 On Sun Systems And Break
7 Using a Serial Console on FreeBSD
8 Security Implications
9 On Conserver Versions
10 Links
11 Manual Pages

1 The Problem

You have a computer room with lots of UNIX® server machines and lots of communications hardware. Each of these machines needs a serial console. But serial terminals are hard to find and quite expensive (especially compared to a much more capable PC). And they take up a lot of precious space in the computer room.

You need access to the console because when things break, that is where error messages go. And some tasks have to be done on the console (e.g. boot problems or OS installs/upgrades). Some UNIX systems allow the console to break out to the ROM monitor which can sometimes be the only way to unstick a hung machine. This is often done with a LINE BREAK sent on the console serial port.

If we are going to play about with consoles, then there are a couple of other things that would be great: