When rebuilding, consider RAID.  Raid 5 provides data security without the cost of mirroring.  The space available under this protocol is N-1.  In other words, if you put in three drives of 250GB each, you get 500GB of space with full data redundancy.  4 drives of 100 GB each yields 300 GB.

If one of the drives goes bad, you plug in a new drive (same spec) an the array will rebuild itself without data loss.  Other than constant backup or a home server, this is one of the cheapest and simplest methods of achieving data redundancy.

Being and engineer (and German), I use both plus an external USB HD for off-site backup of critical data.

Klebnor

Lotus 123 ~ S-Render ~ OS/2 WARP ~ IBM 8088 / 4.77 Mhz ~ Hercules Ultima graphics, Hitachi 10 MB HDD, 64K RAM, 12 in diagonal CRT Monitor (16 colors / 60 Hz refresh rate), 240 Watt PS, Dual 1.44 MB Floppies, 2 button mouse input device.  Beige horizontal case.  I don't display my unit.