700 Concurrent users = BAM! What server setup are you using and would you recommend?
 

I have a website: http://www.londonfgss.com/

And roughly this is a 2GB RAM Slicehost Xen powered Ubuntu box. So it's got 2 x Dual core, RAID 10, stuff like that.

And I've been through the server optimisation process and done everything that eva2000 recommended just short of re-compiling MySql.

And now every day between 9am and 11pm GMT when we have our 700 concurrent users... we see severe server load and eventually things grind to a halt.

Is this the first symptom of having outgrown our hosting?

As in... is it definitively the end of the road for that single machine in it's current configuration?

And, from there... where would you go next? And if you have 700+ concurrent users... where did you go next?

I'm thinking of having a second similar box just for MySql, and leaving this box just to do the front end, but it's Apache that seems swamped and I wonder whether this setup would buy me any major advantage and whether there are better options.

Any advice appreciated.