erik quanstrom wrote:
> do you have a citation for this?  i know if you work out the
> numbers from the BER, this is about what you get, but in
> practice i do not see this 8%.  we do pattern writes all the
> time, and i can't recall the last time i saw a "silent" read error.

Yes, the real numbers are much, much lower, but still significant
because they affect RAID reconstruction.  See this[1] paper.

Some unrelated, but interesting fact from that paper: "nearline disks
(and their adapters) develop checksum mismatches an order of magnitude
more often than enterprise class disk drives".

[1] L. N. Bairavasundaram, G. R. Goodson, B. Schroeder, A. C.
Arpaci-Dusseau, and R. H. Arpaci-Dusseau. An Analysis of Data
Corruption in the Storage Stack. In FAST, 2008
http://www.cs.toronto.edu/~bianca/papers/fast08.pdf

-- 
Aram Hăvărneanu

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