Re: [PATCH 1/4] md: Factor out RAID6 algorithms into lib/

Ric Wheeler
2009-07-17T15:58:24Z

On 07/17/2009 11:49 AM, H. Peter Anvin wrote:
> Ric Wheeler wrote:
>>>
>>> The bottom line is pretty much this: the cost of changing the encoding
>>> would appear to outweigh the benefit. I'm not trying to claim the Linux
>>> RAID-6 implementation is optimal, but it is simple and appears to be
>>> fast enough that the math isn't the bottleneck.
>>
>> Cost? Thank about how to get free grad student hours testing out
>> things that you might or might not want to leverage on down the road :-)
>>
>
> Cost, yes, of changing an on-disk format.
>
> -hpa
>

Putting RAID6 behind us, we still might be interested in the other encodings
that are in:

"A Performance Evaluation and Examination of Open-Source Erasure Coding
Libraries For Storage"

http://www.cs.utk.edu/~plank/plank/papers/FAST-2009.html

since they give us even more flexibility....

ric