Minimum 2 hard disk required. You must use same size hard disk like 2 x 250 GB.
RAID 1 is mirroring and it does provides fault tolerance from disk errors and single disk failure.
Don’t go for software based RAID, use hardware card / RAID, as they are more reliable and performance should be good.
If you cannot purchase RAID card, use P4 computer with 1 Gig RAM to get good performance but software is slow.
If you need any other information just reply back
