RAID 10

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RAID 10

Steve Jones - SSC Editor

SSC Guru

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March 3, 2011 at 9:22 pm

#63717

Comments posted to this topic are about the item RAID 10
March 4, 2011 at 1:46 am

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Henrico Bekker One Orange Chip Points: 27652 More actions · Answer 1

Thanks for the question...these RAID questions are nice, they let you think a bit 😉

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Koen Verbeeck SSC Guru Points: 259115 More actions · Answer 2

Dammit, I got it wrong because of this misleading quote in Wikipedia:

RAID 1+0: mirrored sets in a striped set (minimum two disks but more commonly four disks to take advantage of speed benefits; even number of disks)

On most other sites I've found 4 as a minimum. (after I've answered the question of course)

Damn you Wikipedia, you have fooled me once again! 🙂

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Carlo Romagnano SSC-Insane Points: 22682 More actions · Answer 3

Koen Verbeeck (3/3/2011)
Dammit, I got it wrong because of this misleading quote in Wikipedia:
RAID 1+0: mirrored sets in a striped set (minimum two disks but more commonly four disks to take advantage of speed benefits; even number of disks)
On most other sites I've found 4 as a minimum. (after I've answered the question of course)
Damn you Wikipedia, you have fooled me once again! 🙂

Same for me.

M&M SSC-Insane Points: 21700 More actions · Answer 4

Thanks for the question. I took a chance and got it right 🙂

There were conflicting answers on the net.

Learnt something as well through QotD.

For RAID5 minimum number of drives is 3

For RAID10 minimum number of drives is 4.

M&M

cengland0 SSCertifiable Points: 6102 More actions · Answer 5

I was about to answer 4 from my own knowledge but then looked it up to be sure and found this:

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

It quotes:

RAID 10 can be implemented with as few as two disks. Implementations supporting two disks such as Linux RAID10 offer a choice of layouts, including one in which copies of a block of data are "near" each other or at the same address on different devices or predictably offset: Each disk access is split into full-speed disk accesses to different drives, yielding read and write performance like RAID0 but without necessarily guaranteeing every stripe is on both drives.

Therefore, the correct answer should be 2 like I answered. Usually it's 4 but there is this possibility of 2 and the question asked for the minimum not the "usual."

PurpleLady SSCertifiable Points: 7819 More actions · Answer 6

I went against my better judgement and answered 2 - since I also read

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

Oh well - Nice to know I'm not the only one - though next time I'll trust myself.

Kiara SSCarpal Tunnel Points: 4185 More actions · Answer 7

Well, this time I shouldn't have done the research...

I read the exact article that was quoted in the question, and found this quote:

RAID 1+0: mirrored sets in a striped set (minimum two disks but more commonly four disks to take advantage of speed benefits; even number of disks) provides fault tolerance and improved performance but increases complexity.

So I answered 2, rather than 4. My bad for believing wikipedia, I guess - and my surprise that this article was the one that was cited for the reference.

-Ki

mvelic SSC Enthusiast Points: 133 More actions · Answer 8

Yeah, I think a lot of people are going to get this "wrong" since we read the Wikipedia article. Which, hilariously, is linked in the answer.

paul.knibbs SSCoach Points: 15320 More actions · Answer 9

Hmmmm. If it hadn't linked the Wikipedia article I got the wrong answer of 2 from I'd have been fine, but when the reference quoted in the real answer supports what I said but the answer doesn't...

Mike Is Here Hall of Fame Points: 3348 More actions · Answer 10

I like a lot of people answered two for the same reason

RAID 1+0: mirrored sets in a striped set (minimum two disks but more commonly four disks to take advantage of speed benefits; even number of disks) provides fault tolerance and improved performance but increases complexity

The question was not the best optimal configuration but the minimum.

lance.trahan SSC Rookie Points: 34 More actions · Answer 11

I have to agree that most are going to fail this one because of conflicting information. Question specifies "minimum" not "optimal". 🙁

Surii Default port Points: 1497 More actions · Answer 12

Should have trusted my own instincts. Wikipedia ruined my ans.

Steve Jones - SSC Editor SSC Guru Points: 736504 More actions · Answer 13

I would have sworn that the RAID 1+0 was 4 in Wikipedia, and I have submitted a correction.