RAID 1+0 = RAID 10

plettner

Hi all,

I've been chugging through my Server+ literature (CompTIA Server+ Certification book). Discussing RAID, it says RAID 1+0 is NOT the same as RAID 10. It explains that one channel mirrors data while the other channel stripes the same data. OK. That's fine for me.

But, with that book is a MeasureUp CertPrep exam on CD. One question was in regard to which RAID is best suited to a particular scenario. The answer I chose was wrong. In the explanation they say RAID 1+0 is the same as RAID 10.

Any thoughts on this? To be honest when a book sanctioned by CompTIA says RAID 1+0 is not RAID 10, I'll believe that.

jasonboche

I've always thought of RAID1+0 and RAID10 (disk striping w/o parity with mirroring) as being synonomous.

Low and behold, they are the same:

http://en.wikipedia.org/wiki/Redundant_array_of_independent_disks

http://www.acnc.com/04_01_10.html

http://www.ofb.net/~jheiss/raid10/

Although RAID0+1 should not be confused with RAID1+0 or RAID10

plettner

Upon reading it again, you're right I was talking about RAID 1+0 not RAID 0+1.

"Contrary to some sources [RAID 0+1] is not the same as RAID 10". I must be dyslexic today.

Thanks for pointing out that difference, jasonboche.

Danman32

I have trouble understanding the order myself. Is it 0 encapsulated with 1, or is it 0 after 1?

Now if they were to say 0 in 1, or 0 on 1, that might be easier to follow.
The former would be 1(0), the latter would be 0(1).

I say the heck with all that and just do RAID 5. After all, you have to have 4 disks (or partitions for soft mirror/stripe) to do 01 or 10.

blargoe

1+0 would be mirror sets (Raid 1) which are then striped together (+ Raid 0).

Why would you ever do it like this? Depends on the application. For one thing you can have more than 1 failed disk simultaneously in 1+0 as long as all of the disks in the same mirror doesn't fail.

Look at the wikipedia link provided in one of the above posts, it goes into excruicating detail on the hows and whys.