Need Suggestions: Ideal 2 server configuration for active & fast-growing big forum
 

My forum is decent size, and growing pretty quickly (30-40 new members every day).


Forum quick stats:

• Members: 20,000+
• Posts: 1,100,000
• Threads: 87,000+
• Online Users Avg: 300
• Online Users Peak: 600-700

Currently I am on a fairly robust single server, see this thread for details:
Server Optimization Request

However, my forum is starting to outgrow this hosting solution, and probably pushing the edges of what can be done using a single server.

My next step is probably moving to a 2 server solution, one for webserver, one for DB only. As my forum is growing very quickly, this will inevitably become necessary at some point, so making the change sooner rather than later is probably wise.

I have heard very good things about Softlayer as an ideal host for large vBulletin sites. I will probably be configuring and pricing out new servers for this 2 server platform over the next couple days.

I have been researching the ideal configurations of the servers for this type of implementation, but would love to hear your suggestions. Could you give your suggestions for the following for both the webserver and DB server:

• Preferred OS & version, kernel version
• MySQL version: Currently I use 4.1.22, should I move to MySQL 5.x when making the server move? If so, what precise version? Would there be any issues importing my 4.1.22 databases into 5.x if I make the switch? Any special install options preferable?
• PHP version: Currently on 4.4.7. Would it be preferable to move to 5.2.5? Also, any particular compile preferences when having php installed?
• HD Type: I have seen 15k rpm RAID 10 recommended for large forums. Would this be ideal for both the webserver and the DB server?
• Processor: Dual Dual-Core Xeons would be ideal for both servers I assume? Any particular chipsets work best for each server?
• RAM: 4 GB ECC RAM on each server would be ideal?
• Any other guidelines or suggestions on configuring optimal server platform for an "ideal" vBulletin 2 server implementation.

My goal is to be able to give my forum room to grow, and be able to host upwards of 1500 avg concurrent users. I don't mind having much more power than I need right now, since my forum is growing very quickly, and expected to increase that pace over the next 8-12 months (this is related to the topic of the forum itself, and the expected large influx of new users).



Thanks for any helpful suggestions to aid my search for an ideal host/ 2 server config for my site.

Quite frankly, you sound like you're in over your head just a tad. I'd recommend giving steve @ rack911.com a shout -- he's great with large forum configuration / optimization setups and even handles hardware recommendations.

He's setup a few forums on my behalf.
On the other hand, re: your questions.

In this case due to the high IO I'd highly recommend having SCSI for both systems. While softlayer might seem like a good choice, they're really not. Their infrastructure: great. Their support: piss-poor.

CentOS all the way! :)
//My two, random cents.