>Depends on how much you want to spend. ;)
>
>Typically in a clustering scenario, both servers access the same hard disk via SCSI or Firewire. These protocols allow multiple computers to share the same drive (a RAID array, actually) directly without going through a slow network. However, such solutions are considerable more expensive than a standalone server with an IDE drive. If you want to use less expensive hardware, you should consider using a fast network (1 Ghz or fiber) between the web servers and the data server.
>
>However, it really depends on your application and its usage. Caching is different on local and network drives, for example. You probably should determine the network load by moving the database to a different computer and monitor performance reduction and used network bandwith.

In that situation, a consideration to go with a share array will probably be implemented for the next level. As for now, the current amount of money invested will fit ok by tripling the server power.