How to split the database into servers? (reduce server load)

After reading the thread discusing how many servers your board was on. I wondered how do you guys split the DB into those servers.

Maybe some of you make the writes go to one server, reads from another and searches from a third one.

The question is, how can I do this? I am really interested in knowing how to do it. Any help or guidence would be great!

[slappy]

You might want to start with a read of this Thread by Erwin on vbulletin.com, titled:

How-To: Split Web and Database into 2 separate servers

http://www.vbulletin.com/forum/showthread.php?t=185705

Regards,

[COBRAws]

Thank you slappy!