Note: You’re going to need to know the basics of setting up your own virtual host for Apache 2 to make use of this. If you don’t know how to do that you could probably find a tutorial on this blog if you try hard enough

Open up the config file for your virtual host with your favourite text editor:

pico /etc/apache/sites-available/mywebsite.com

It should look something like this:

<VirtualHost *>
DocumentRoot /home/mypage.com/www/
ServerName mypage.com
ServerAlias www.mypage.com
ErrorLog /home/mypage.com/log/
CustomLog /home/mypage.com/log/
</VirtualHost>

Before the closing tag add links to your custom error pages, it should look like this:

ErrorDocument 403 /403.php
ErrorDocument 404 /404.php

Now save the file, restart apache by typing:

/etc/init.d/apache2 restart

If you haven’t created those custom pages yet, do so now or you’ll end up with a rather funny looking error page that tells you there was a 404 error while trying to find your custom 404 page.  You can make it simple, just the general look and feel of your site with a friendly message of what happened.  Or you can touch it up throw a custom search box that will allow them to find the proper file on your site. For that I will let Google give you the step-by-step.

For an example of a good 404 page, check out NiagaraForFree’s custom page.

Updated: March 10, 2009 for Ubuntu 9.04