@Alex Lee

What's the performance of your SATA drive vs a SAS drive?

While the SAS drives don't have the larger storage capabilities of the SATA drives, they are faster.

The good thing is that with 2.5" drives in a 2U high server, you could put a set of 7 disks of SAS and a set of 7 disks of SATA in different raid configurations. With mulit-core xeon chips, your single server could now be both a web/mail/app server and a database server.

Add in redundant power supplies and you've got yourself a box that most SMBs would love.

Double this and use HDR on the database along with load balancing of your web app, and you have extremely good uptime and reliability for a very low relative price. (relative to what it would have cost you 5 years ago.)