Risk of RAID0

Blue|Fusion · Posted: Sat, 24 Jun 2006 03:19:28 Post Subject: Risk of RAID0

Well, before I go off to to college in August, I'm wiping and re-installing Gentoon on my desktop. Before doing so, however, I'm trying to decide if I want to use a RAID setup (for performance gains) or leave it as is with independent drives. I have 3x 160GB Saegate SATA-II drives. I really don't use that much space. I'm a performance hog, and any tweak I can get I go for it, usually despite the risks, however I don't know much about this RAID stuff.

So I have RAID 0, 1, 5, and 10 on my motherboard's ICH7R controller. I've eliminated the option for RAID1 as that's not a performance gainer, just a mirrored drive. RAID5 is slow when it comes to writing, so forget that. RAID10 looks promising, but I'd need to go buy another disk for it, and although I don't use that much space, it's always nice to have it.

That leaves me with RAID0. So here's what I know. If one drive in the array dies, I'm SOL. The question I pose to you, who have done more computer hardware work than I, is how likely is it that a drive will die? I have never had a drive die on all the computers I've worked with. With that said, they've all been OEM equipped, either Dell or Crapaq, save this one, which is still realatively new.

So would it be worth the risk of going RAID0 with two disks? With three disks? What kind of performance improvements would it offer? Currently, I get between 67 and 69MB/sec read speed from each drive. Would write speeds be slower, faster, or pretty much the same?

As I've said, I never really work with RAID before, but want to get with the times and get as much speed as I can.

**Doctor Feelgood** · Posted: Sat, 24 Jun 2006 09:10:28 Post Subject:

I wouldn't do it if these were my only data stores. Regardless of performance boost, the potential to lose it all is not worth it to me.

In the past few years I have had a few drives die, from Maxtor (3), WD (1), and Seagate (2), so it doesn't matter what the drive specs are or who made it. They can all die.

The numbers above may not be fair, as the 2 Seagates represent a total of maybe 8 drives, while it is 1 of 1 WDs, and 3 out of 6 Maxtors. All with in warranty, but still a pain. And two times the drives were in RAID arrays when they died. RAID 0 for one of the Maxtors...

So, if you do it, have that RAID 0 array backed up, at least the critical bits, to a third drive, optical media, ftp, or something.... Presently I have my various PCs all back up to two places using http://www.2brightsparks.com/freeware/freeware-hub.html - but for a Linux install, I am sure you know what to do anyway.

College this fall, ehh? Cool... Cool

BeerCheeze · Posted: Sat, 24 Jun 2006 11:47:53 Post Subject:

Well if you're will to spend the money...

Put 2 drives in RAID 0, make these your Boot/OS/App drive, then put the other 2 in RAID 1 and have them as your data storage drive. There for you end up with 2 drives, and get both performance and reliability.

However, if you don't want to do that, and just want to stick to RAID 0... back up your data, cause you lose 1 drive all data goes bye-bye.

Blue|Fusion · Posted: Sat, 24 Jun 2006 12:33:10 Post Subject:

Hmm, that's not a bad idea, EC. I don't need thee RAID1, but RAID0 for main OS and the third drive for data storage (music) might work out nicely.

I think I'll try some software RAID in an older PC here and see how well that works out. If it's good, I'll go with the BIOS RAID on this desktop.

**Doctor Feelgood** · Posted: Sat, 24 Jun 2006 12:37:30 Post Subject:

Software RAID is going to take a performance hit as basically the OS is trying to do what an independent hardware RAID controller should be doing.

BeerCheeze · Posted: Sat, 24 Jun 2006 14:37:55 Post Subject:

Hardware RAID ONLY!

Blue|Fusion · Posted: Sat, 24 Jun 2006 15:22:35 Post Subject:

So what is BIOS RAID considered? I know it's not a true hardware controller, but since hardware is involved, is it a softare controller? I've read BIOS RAID being on both sides of the fence, and not sure which it is. And I still don't feel like spending more money for a RAID controller. If I do, I'm getting a SCSI RAID controller and some 15k RPM drives...which isn't going to happen.

**Doctor Feelgood** · Posted: Sat, 24 Jun 2006 15:46:46 Post Subject:

Oh, the onboard hardware RAID controllers have settings in the BIOS, but that isn't software RAID.

DragonMaster · Rated NC-17 Joined: 31 May 2006 Posts: 134

When a drive dies in RAID 0 I just see it as if you lost your only drive in a normal setup. The only HDDs I have that died were a 6.4GB and 20GB Maxtor, a 500MB Quantum and a 400MB Seagate. The two last ones died because I dropped them (Doh!), the 6.4GB because it was idling and I tilted it a bit (WTF? the Quantum 3.2GB next to it is still OK) and the 20GB, because it was dead when I got the gifted computer it was in.

Das Capitolin · Posted: Sat, 24 Jun 2006 19:29:57 Post Subject:

And here comes the correct answers:

RAID-0 (striping) is great for performance because it splits the read and write times in half. The most major downside is that if data corruption occurs, the drives become out of sync, and you are SOL. You don't need a drive to go bad, just to have a drive record corrupt data (improper shut down, power out, crash). I have build 11 systems for customs requesting RAID-0 arrays (using 10k Raptors), and 9 have been back for corruption within the first year and become non-RAID systems.

As far as mainboard based RAID, the ICH-6R and 7R chipsets are HBA hardware RAID controllers; anyone who claims they are software is clueless. HBA stands for Host Bus Adapter, and has very few disadvantages over an add-in RAID controller. Those disadvantages are: 1) HBA RAID utilizes your CPU, rather then a true I/O RAID processor found on add-in's. 2) HBA RAID is O/S dependant; meaning it doesn't work with every O/S. 3) Less feature set then an add-in RAID controller.

I hope this helps. I just wanted to get this topic back on track with solid advice.