DIY External Raid5 [Archive]

doubleJ

11-11-2006, 05:14 PM

Hello...
I was wondering if there were any diy raid5 kits.
I have 1 wd2500yd (sata2) and I'm considering buying another. When the time comes to buy a third, I would like to raid5 them, but I would prefer an external setup (usb2/firewire). Really, just a case/psu/raid5 controller (sata2) is what I'm looking for.
Is there anything like that? I don't want to buy a full kit for a couple grand.
Really, I have power supplies and stuff, so a case with a built-in controller would rock. Basically, what is there available?
JJ

unhappy_mage

11-11-2006, 07:25 PM

Generally it's simpler to put everything inside your machine. Supermicro makes some really nice 5-disk in 3 5.25" bay racks (http://supermicro.com/products/accessories/mobilerack/CSE-M35T-1.cfm) - I own one and it's really nice. They're about $130, and a raid card runs from about $250 for the Highpoint 2220 up to $500ish for the Areca series. The Highpoint is implemented with software; the Areca is a hardware solution, so thus the price difference. If you're running things that pound on the disk a lot and use a lot of CPU at the same time, the Areca will perform better. Otherwise they're about the same in terms of performance.

If you really want an external solution, you can get a card like the Highpoint 2322 (http://www.highpoint-tech.com/USA/rr2322.htm) or Areca 1231 (http://www.areca.us/products/html/pcietosas1280.htm) (it'd require an internal-to-external bracket), along with any of the plethora of 4-bay multilane enclosures out there. They should work fine - but notice that creating a raid 5 array over 2 enclosures is un-recommended, since it could cause the card to destroy the array if one of the enclosures isn't plugged in.

http://www.hardfolding.com/ftag1.php/mem/150072.png (http://www.hardfolding.com?go=38&tm=33&id=150072)

Dually

11-12-2006, 07:54 PM

Take a look at this case (http://www.cooldrives.com/fonasamidren.html) ... it's on sale for a reasonable price.

They have also have a SATA II Port Multipler (http://www.cooldrives.com/cosapomubrso.html) and/or a SATA Multi Lane Bracket (http://www.cooldrives.com/musaenscopde.html) that you can with an existing external drive enclosure.

mikeblas

11-13-2006, 12:36 AM

Hvatum

11-13-2006, 01:40 AM

"External" as in a NAS? US Robotics (http://www.directron.com/usr8700.html) has started making such boxes.

"External" as in a box that does RAID, then interfaces back to the host machine? (Some people call this "Direct attached storage".) Promise (http://www.promise.com/product/segment_list.asp?segment=UltraTrak) makes such kits.

Cool. The price for that US Robotics device is pretty high though. For that much I would just build my own Linux RAID box running in a MicroATX case or some such.

stevewm

11-13-2006, 01:31 PM

If you are using WD drives for RAID, you will want to use the "RE" edition drives. These are the same drive, with some slight modifications to support better use in RAID arrays. Specifically how long the drive takes to response in the event of a read error. "Time Limited Error Response" is what they call it.

Normal drives take too long and cause some RAID controllers to think the drive is dead when it is in fact not dead.

doubleJ

11-13-2006, 02:38 PM

The wd2500yd is re (note not re2, though).
Thanks for the ideas...
Given the prices, it might just be better to build another machine with raid5 and gigabit networking. My initial idea was direct-attached (usb2/firewire). Then the array would be controlled at the external box and any computer could just access it as an external drive.
Basically, I'm building quite a data store and I really don't want to lose it (duplication business iso's). My single 250GB has <10GB free.
JJ
If you are using WD drives for RAID, you will want to use the "RE" edition drives. These are the same drive, with some slight modifications to support better use in RAID arrays. Specifically how long the drive takes to response in the event of a read error. "Time Limited Error Response" is what they call it.