On Sat, 19 Jul 2008 00:51:40 -0400, David T. Ashley wrote:

> b)I've noticed that on Dell's web page, if one configures a server for
> RAID 1, it typically requires a separate disk controller. Why is this?
> Does RAID 1 require special hardware support?

If you have one controller and two drives one of the drives can fail.
If you have two controllers and two drives one of the controllers or one
of the drives can fail.

It's just an added level of redundancy... and depending on the hardware,
may improve performance.