We've got an issue with one of our servers that hosts multiple drupal sites. It was running just fine, and now there's a problem. We're looking to see if there are any other issues causing the server slow down. We're also reassessing our server requirements and so what kind of machine would we need - how many sites can you run serving what n number of requests? I know there's a bunch of variables, how many modules etc... but i'll try and be as specific as possible.
Current: 2.4 GHz 4MB Cache Intel® Core™ 2 Duo processor + 3GB RAM 2x 250GB Harddrives, Centos + PHP (5.2.6) & APC (3.0.19) + MySQL (5.0.45)
So say we wanted to host around 20-30 sites on a single server (drupal6), serving 500k page views per month across them all. With core modules + views, cck, panels, 4-5 with ubercart, and a few other modules so apart from the 4/5 ubercart about 10 modules per site.
So what can you realistically serve off a single machine?
Update the slowdown was caused by a spambot continuously posting comments to one of the sites, causing spikes in cpu usage and heavy disk access. Still though wonder what you can/ can't serve/ off a single machine.