RAID 0+1

[SlickRoenick]

How many physical hard drives does it take to pull this off?

 

[Lord Evermore]

4

 

[SlickRoenick]

And you are 115% sure that it is 4 disks and there is no such math/algorithm/Galois Theorem/etc that can be done to show that it could also happen with just 2 disks?

 

[Lord Evermore]

http://en.wikipedia.org/wiki/RAID#RAID_0.2B1

It's at least 4, because you have to have 2 drives to create a RAID 0 array, and then 2 drives to mirror that array to.

Of course you could on some controllers maybe set up a single drive as a "striped" array, but it wouldn't actually be RAID and wouldn't provide any performance increase, and then mirror that.

 

[Blain]

Intel Matrix RAID can sort-of do 0+1 with 2 HDs.
It's not a true 0+1, but it does pull off good performance.

 

[Lord Evermore]

Matrix RAID lets you put two separate volumes on the drives, one can be RAID 0 and the other RAID 1 (or one can be RAID5), but the RAID 1 volume is essentially just a separate mirrored partition. It's not mirroring the RAID 0 array, so this isn't actually RAID 0+1, it's just two different RAID arrays using partial capacity of the drives for each, where other brands just treat each drive in an entire block. It lets you get improved performance for some of your data, while providing security for the other volume, but not both at the same time.

That GamePC article is misleading in saying that Matrix RAID brings 0+1 to the masses, as Matrix RAID does not support 0+1. Matrix RAID apparently supports RAID 10 (striping a mirrored array) but still requires 4 hard drives.

 

[Blain]

Originally posted by: Lord Evermore
Matrix RAID...
isn't actually RAID 0+1

Disclaimer...
"Intel Matrix RAID can sort-of do 0+1 with 2 HDs.
It's not a true 0+1"

 

[Lord Evermore]

It's not even "sort of". It's just RAID 0 and RAID 1. It's not the least bit related to mirroring a striped array. There's no such thing as "sort of" doing it, it either is or it isn't.

 

[Fullmetal Chocobo]

Originally posted by: Lord Evermore
It's not even "sort of". It's just RAID 0 and RAID 1. It's not the least bit related to mirroring a striped array. There's no such thing as "sort of" doing it, it either is or it isn't.

Funny, some people feel the same way about "RAID" 0, instead calling it "AID 0", etc.

 

[Lord Evermore]

Well you know, they do tell you in the name how much RAID you get - zero. It kinda is well named.

 

[Fullmetal Chocobo]

Originally posted by: Lord Evermore
Well you know, they do tell you in the name how much RAID you get - zero. It kinda is well named.

LOL... Woohoo! I get 5 RAIDs. ROFL.