RAID 1, 5 clarification?

[haxxorpoop]

I've got a new computer that I'm building, and I want to implement either RAID 1 or RAID 5 using the 4 x 500 GB drives with the computer, but first I need clarification on certain things. I will be using Windows XP, and my motherboard has an onboard RAID controller. Also, I dont really need the extra space, and redundancy is my top priority.

RAID 1:

• If the motherboard dies, I am still able to recover all my information, correct? That is to say, upon a dead motherboard, the 4 drives can be plugged into a new computer, and 2 drives will be mirrored correctly with the other 2 drives (at which point I can re set up the RAID).
• Windows XP doesnt natively support software RAID 1, correct? But this shouldn't be a problem for me, since I'm doing a hardware RAID with the onboard controller.
• How setting up 2 mirrors work with only 1 hardware controller? Is this recommended?

RAID 5:

• Does RAID 5 require a minimum of 4 drives or a minimum of 3?
• If the motherboard dies in a RAID 5 setup, data recovery will be difficult, perhaps impossible, no?
• RAID 5 is a hardware-only implementation of RAID, correct?

Thanks for the help, guys (and gals ).

[Solid Snake]

If you use hardware RAID5 and your motherboard blows, you'll need to replace it with one that has the same RAID chipset. RAID5 drives cannot function outside of the array as independent disks. RAID5 has been implemented in software in Linux. Using software RAID5 will at least give you a chipset-independent array that you can take to another motherboard if it fails. RAID5 requires at least three disks and will give you a minimum of 66% storage efficiency, increasing with the number of disks. If more than one disk fails, you will lose everything. Adding drives to a RAID5 decreases reliability and write performance while increasing read performance and storage efficiency.

RAID1 disks can function outside of their arrays. Since there's no data striping or parity, there's no need for a RAID controller to set it up in a proprietary way. You should be able to rip out a RAID1 system disk, stuff it in another computer and have it boot. RAID1 will give you at most, 50% storage efficiency (with two drives), but the best protection for your data. Adding drives to a RAID1 will increase reliability and read performance, while decreasing storage efficiency and leaving write performance mostly unaffected.

If your data is important to you, use two of those drives as a bootable RAID1 array, and at least one of the other two as backups (not in the actual array). RAID is no substitute for backup.