Heh, I had a bunch of questions, but
http://www.servermatrix.com/servers.html
seemed to answer them (I just looked at what they offered).
Remaining questions:
1) Which version of mysql is installed, using what sorts of tables?
2) What filesystem do they install on the server?
Comments:
1) To those who suggested the AMD64 architecture - I wouldn't consider Linux's AMD64 support ready yet for prime time, and I have a cluster of them. Making it work reliably is still iffy, and the server hardware that I've seen I wouldn't consider extremely reliable. Regardless, the company that hosts scubaboard doesn't currently support it.
(in regards to future scaling)
2) Have y'all done profiling of your mysql server, and what queries are being run from memory, and which are requiring disk i/o ? With the proper tuning, you should be able to get everything used for rendering a typical vbulletin page into system memory.
3) If you have the administration skill, the Linux 2.6 kernel series has made some noticeable improvements in performance and scalability.
4) You've probably already considered it, but a Squid reverse proxy in a httpd-accelerator configuration in front of your Apache configuration could potentially reduce disk hits and improve site responsiveness, as well. It is possible to explicitly specify how much ram is used for cached objects, so a truly large number of commonly accessed objects (smilies, logos, etc.) can be served directly from RAM without ever hitting the disk.
5) It's worth asking the vbulletin folks if there are any known issues, but there is a free PHP cache add-on available at
http://turck-mmcache.sourceforge.net/ . This eliminates some i/o, and the processing required to repeatedly compile unchanging PHP scripts.
I'm sure y'all already knew some or all of that, but hey it was a chance to open my big mouth on stuff I work with a lot, I couldn't pass up
Good job on the site,
jeff
