help w/RAID setup

[Jim Bancroft]

I'm getting a new motherboard and two SATA hard drives soon and would like to establish a RAID set. Haven't decided which brand of motherboard I'm buying, but all the contenders have RAID 0/1 capabilities.

Problem is, I don't know the difference between RAID 0 or RAID 1 or RAID 0+1. Are there any websites that explain these choices and talk about which is most practical for home-use? My goal is to keep chugging along if one drive dies and I'd like the most "maintenance free" RAID choice possible. Peak performance on the RAID set isn't vital, though I won't complain if it's there. If you've got an opinion I'm glad to hear it!

 

[imported_ecosoft]

Dear Jim Bancroft:

I've run a number of different RAID arrays ... the only reason, unless you are running a Server that needs ultimate uptime availability, is for raw I/O speed. Therefore RAID 0 (striping) with (3) identical drives in the array works best, but it's expensive. Recently some folks tested RAID vs a bare 7200RPM ATA100 HD and found no practical difference in absolute I/O speeds! Therefore, why hassle with RAID? Remember, one tiny hiccup during RAID I/O can wipe the array, and if it's a RAID 0 you are hosed, unless you have a tape system and a current backup.

You didn't mention what mobo you are considering. Based on what's now available, I'd recommend a socket 939 Athlon64 w/90nm 3200 CPU (low heat), Micron Ballistix memory, and WD 10K SATA drives, which can be connected non-RAID. If, your heart is set on "RAID'ing" your existing system, get a (2) channel PCI ATA RAID controller, and most importantly Roxio GOBACK. GOBACK writes a disk profile at each boot, so if ya' get dorked, reboot and invoke GOBACK to the last previous "good" configuration. (That's saved my butt a number of times.)

The very cheapest way to get improved I/O speeds is to take your existing system, bump up the FSB about 6MHz i.e.: 133 to 139, 166 to 172, set memory timings to the lowest stable (fastest speeds) and then, add an ATA 7200 HD with 8MB cache. A WD800 80GB 7200RPM w/8MB cache is about $60 at Newegg.
Good luck

 

[dclive]

Originally posted by: ecosoft
You didn't mention what mobo you are considering. Based on what's now available, I'd recommend a socket 939 Athlon64 w/90nm 3200 CPU (low heat), Micron Ballistix memory, and WD 10K SATA drives, which can be connected non-RAID. If, your heart is set on "RAID'ing" your existing system, get a (2) channel PCI ATA RAID controller, and most importantly Roxio GOBACK. GOBACK writes a disk profile at each boot, so if ya' get dorked, reboot and invoke GOBACK to the last previous "good" configuration. (That's saved my butt a number of times.)

GoBack will only prevent OS issues (you install a driver and BSOD the box on boot, for example, and don't know how to fix it), but won't do anything to prevent the main issue with RAID0 - if a single drive dies, the entire array is toast and all data is lost.

My suggestion, as you said, is for the OP to simply purchase a single fast SATA drive, like the latest Raptor.

 

[dclive]

Originally posted by: Jim Bancroft
Problem is, I don't know the difference between RAID 0 or RAID 1 or RAID 0+1. Are there any websites that explain these choices and talk about which is most practical for home-use? My goal is to keep chugging along if one drive dies and I'd like the most "maintenance free" RAID choice possible. Peak performance on the RAID set isn't vital, though I won't complain if it's there. If you've got an opinion I'm glad to hear it!

RAID1 gives you redundancy, and RAID0 gives you speed. RAID0+1 gives you both.

RAID1 takes 2 drives that are mirror images of each other - 2 40G drives give you 40G of usable storage, and if one drive dies there's no issue - it will still work.

RAID0 takes 2 drives that are striped to each other - 2 40G drives give you 80G of usage, fast storage. If either drive dies, you lose everything.

RAID0+1 takes 4 drives that are mirror images AND striped to each other. It gives speed and reliability, but takes 4 drives. It's faster than RAID1, and also offers RAID1's redundancy - if a single drive dies, you're still OK.

 

[Jim Bancroft]

Thanks for the explanations. How much of a performance hit can I expect if I roll with a RAID 1 setup, which sounds like what I should be aiming for?

 

[SeTeS]

The performance hit will be during writes. I'd say that you won't suffer much. Reads will happen in parallel, so you can expect a little boost there.

Raid 1 will really ONLY protect you from physical failure. If your files get hosed via the os (by any action, you trashing them, virii, etc.) then they are hosed on the mirror drive as well. No help there. But if drive 1 craps out (bad sectors, heads, etc), drive 2 should have you covered.

Raid 0 reads and writes in parallel, but one physical failure results in complete data loss, as each physical drive contains "half" of each of your files (this is a simplified example, I know).

Honestly, I've been running raid 0 for 6 years now and have only had one failure. And THAT was due to those dastardly IBM 75GXP's. Since then, maxtors have given me no problems.