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

Ric Wheeler
2009-07-17T15:35:46Z

On 07/17/2009 11:20 AM, H. Peter Anvin wrote:
> Ric Wheeler wrote:
>>
>> Worth sharing a pointer to a really neat set of papers that describe
>> open source friendly RAID6 and erasure encoding algorithms that were
>> presented last year and this at FAST:
>>
>> http://www.cs.utk.edu/~plank/plank/papers/papers.html
>>
>> If I remember correctly, James Plank's papers also have implemented
>> and benchmarked the various encodings,
>>
>
> I have seen the papers; I'm not sure it really makes that much
> difference. One of the things that bugs me about these papers is that he
> compares to *his* implementation of my optimizations, but not to my
> code. In real life implementations, on commodity hardware, we're limited
> by memory and disk performance, not by CPU utilization.
>
> -hpa
>

Fair enough - I thought that his coverage of the other open source friendly
encodings beyond RAID6 was actually quite interesting.

If you have specifics that you found unconvincing in his work, I am pretty sure
that he would be delighted to hear from you first hand. James seemed to me to be
very reasonable and very much a pro-Linux academic, so I would love to be able
to get him and his grad students aligned in a useful way for us :-)

ric