[tahoe-dev] "Why Raid 5 stops working in 2009"

[Aleksandr Milewski]

http://blogs.zdnet.com/storage/?p=162

I'm not sure I agree with his conclusion, but it's an interesting  
point. Essentially he's saying that storage is now so large that you  
can't rebuild a large RAID 5 with a dead drive, because the rate of  
unrecoverable random bitflips is such that one or more will likely  
occur in the rest of the drives, leaving you dead in the water.

And thus RAID-6 is necessary for large RAIDs if you actually want to  
recover. Or, something like tahoe, which is really application-level  
RAID.

-Zandr