Adding RAID to a PC?

Depends upon the type of RAID you want. If you want simple 0+1, you only need two disks. If you want RAID 5, you'll need at least three.

There are RAID cards sold for PCI busses that will take the load off of the CPU (as in a software based RAID solution).

Here's what I want to achieve. Perhaps you will know what I need to do it.

I have a small business office, and just need a RAID system to back up my business files automatically since getting employees or myself to do that reliably is nearly impossible.

My understanding is that with RAID, all my files are simply duplicated to a second on-board HD. That way, if a drive fails, I have a 100% exact copy.

As far as your last sentence goes, I have no idea what you mean (I'm not the brightest tool in the shed, LOL).

Thanks,

General Tsao

What you are talking about is mirroring. You can do this many ways, but I'm not really familiar with the Windoze way of things. You can also simply copy the disk manually.

RAID and mirroring are closely related, but they aren't exactly the same thing.

Since no one else has replied, let me see what I can find out for you. In my world, I use a software mirroring tool to mirror system disks and RAID-5 for data disks. Safe, cost effective, and very little downtime. But I'm a Unix guy.

RAID systems will protect against hardware failure, but they are not a substitute for a good backup practice. Given a choice between RAID and tape backup I would definitely suggest the tape backup.

Benefits of tape backup:
1) Protects against accidental or malicious file deletion/modification. I've restored more files because someone clicked on the wrong thing than I have because a disk went bad.
2) Off-site storage of backup media. Always store your backup tapes at least 100 yards from your live data.

Thanks for all your help!

Perhaps RAID is not what I want after all...

I'd suggest an outboard backup system - huge USB2 and/or FireWire external hard drives are relatively cheap, and easy-to-use software which fully automates the backup process likewise is widely available and affordable. Get more than you think you're gonna need, but there's no need to go nuts ... a few hundred bucks will get you in great shape for a long while to come. Any more than that likely is gonna be mostly just showin' off.

PCI cards are readilly available and for a simple two drive mirror quite affordable
reputable manufacturers being Promise, Highpoint, 3ware, LSI Logic
but it is highly recommended that you employ matched HDDs of the same make and model

a few notes 0+1 is a nested array and requires 4 drive minimum
2 striped drives and 2 more to mirror of the stripe array
0+1 or 1+0 (lerss common) offer both performance (for applications that can employ it) and redundancy

a simple mirror is RAID 1
a simple strip is RAID 0

parity levels being 5, 3, 50, 30 (last two also nested arrays) ect offer advantages in efficiency
the minimum number of drives needed for a RAID 5 or 3 being at least three drives, storage efficiency increases as the number of drives in the array increases,
(total storage being an additive of the number of drives minus one drive)
but while they are quite good a reads, there is a performace penalty with writes, and unless the card has a dedicated XOR processor,also its share of CPU usage

with a simple 2 drive mirror, you should be OK with both the power supply you have in an OEM box (would require about 2 amps more on the +12V rail to spinup the drive, dropping to a 1\4 of that after its spun up) and the thermal solution of the box should be able to deal with it as well, as to if you have a bay available, youd just have to look

some aditional reference
Redundant Array of Inexpensive (independent) Disks @ Storagereview (Reprinted from the PC Guide)
RAID I: The Lesser Levels
RAID II: A Matter of Parity @ Lost Circuits part of the As the Hard Disc Spins Series

as mentioned there are a great number of hazards that can take both drives at the same time, filesystem corruption that isnt physical media, power issues, malware ect.