RAID Controller Questions

k_rock923

Distinguished
Feb 18, 2010
14
0
18,510
Good afternoon. I'm working on putting together a new build, with this motherboard:
ASUS M4A89GTD - http://www.newegg.com/Product/Product.aspx?Item=N82E16813131631

I'll be dual booting Windows/Linux from an SSD and sharing data between them with a RAID array formatted NTFS.

Let me preface this by saying that my experience with RAID setups is mostly with HP servers, which all have real hardware raid and present a single drive to the OS.

Now, I have a few questions about the array setup. I'd like to do RAID 5, with 4 2TB drives. I originally picked out the following drives: Western Digital Caviar Black WD2002FAEX http://www.newegg.com/Product/Product.aspx?Item=N82E16822136792

I'm trying to figure out whether I need a hardware controller and if so, which one to get. I'm a little hesitant to trust the on-motherboard controller with RAID 5, especially with multiple operating systems involved. Maybe it would work okay - not really sure.

I'm suspecting that I need a controller, though. Someone mentioned that they had a good experience with this in another thread: http://www.newegg.com/Product/Product.aspx?Item=N82E16816115094 That seems very cheap for this application, though. Additionally, would I need to upgrade to Western Digital RE drives for any type of controller card setup?

Please don't hesitate to ask for any clarifications. I'm just trying to figure out the best way to go from here, even if that ends up being "use individual disks and forget about RAID".
 

Rusting In Peace

Distinguished
Jul 2, 2009
1,048
0
19,460
I believe that card is a software raid card so it may not perform that much better than the onboard raid?

Can't say I recommend using exactly the same drives in a RAID 5 array. Consider choosing drives from different manufacturers - drives from the same batch are likely to fail at the same time.
 
Western Digital's specification sheet for the WD2002FAEX shows that it has an unrecoverable read error rate of one error per 10^14 bits read. That means you have as much as even odds of seeing an unrecoverable read error each time you read about 10TB of data.

A 4-drive array of these contains 8TB of recorded information. This means there's a very high likelihood of NOT being able to recover from a disk failure with RAID 5. That basically means, IMHO, that RAID-5 is useless with these drives. I'd suggest either looking for drives with a better reliability rating, or finding a controller that can do RAID-6 to avoid the single-point-of-failure problem with RAID-5.
 

r0ck3tm@n

Distinguished
Sep 27, 2009
136
0
18,690
I'm going to say straight away that you should use a hardware raid controller. Looks like that one is? I only know about Adaptec controllers. Definitely use RAID drives though. I use WD RE4's and recommend the same to you. And yeah, I think RAID 5 is overrated. I use RAID 10 and RAID 0 with weekly disk image backups.