How does RAID 6 work?

[We Multiply You]

I would like to know exactly how RAID 6 works. I would be thankful if anyone could explain me how it works. I know that such an array can stand losing up to two drives and rebuilding them before a data loss and that it only uses two drives in the array for redundancy but I have a hard time understanding how data can be duplicated without taking twice as much storage space.

I hope someone one this forum knows how it works, and I look forward to understand more about this array.

 

[~Darkseeker~]

From what i can tell, its the same as RAID5, but with an extra parity block. RAID5 works because it needs 3 or more disks, and you need 2 disks to stripe (half data to both disks) and the extra disk means even if one fails, the other two can keep working in a striped fashion. The extra parity block means that after one fails, there are still enough disks left for another one to fail and the stripe to carry on working.

Diagram of a RAID 6 setup, which is identical to RAID 5 other than the addition of a second parity block

yeah, so just read on on RAID5 and RAID0. Understanding basic striping and basic striping parity will help you understand RAID6.

 

[berry120]

For info, this is a bit of a split carrying on from this thread: http://www.computerforums.org/serve...ge-server-lowest-cost-104220.html#post1072026

I personally disagree with your view that you need to understand something fully to use it. You can read the time without understanding the electronics inside a clock, you can use a computer without understanding quantum mechanics. As long as you know the performance characteristics of RAID 6, and you know that it can reliably withstand any two drives failing, that's really all you need to know.

I understand the ideas and to some extent at least, the maths behind how they work. But trying to explain this to someone who describes himself as the following:

As you may understand, I have absolutely no computer knowledge at all

(taken from the other thread) is not going to be a walk in the park!

However, if you really want to understand fair play. You say you've read around the Wikipedia article and others and still don't understand how it works. What don't you understand? It'd help to know exactly what, since otherwise we'll probably be barking up the wrong tree with another explanation you don't understand.