VBulletin 4 extensive optimization guide

This guide mostly provide things, that are safe to your server or could be easily rolled back. However, please keep in mind, that you apply them on your own peril.
If

• you have RedHat or CentOS operating system on your server
• your forum have around 200.000 – 400.000 posts or more
• your forum have around 100 users online or more at regular daytime
• you have root access to your forum machine and are willing to provide me with root password
• you are willing to report optimization results after some time on vbulletin.org

I'm going to talk with my host to see what we can do here, our forum is a bit small for most this but maybe there are a few things we can tune up.
Here is the full article, check it out and let us know if you have any questions.

http://www.fractalizer.ru/frpost_429/fractalizer-vbulletin-4-extensive-optimization-guide/