[ale] Confusing RAID Performance

[jhubbslist at att.net (Jeff Hubbs)]

On 2/2/11 2:15 PM, scott wrote:
> Remember that RAID6 is slower than RAID5.  RAID5 calculates the parity
> once.  RAID6 does it twice.  This is to make sure that you have parity
> protection incase you drop a drive. I would only recommend RAID6 on
> large drives (1TB or larger).
I sure wouldn't.  For >=~1TB drives, the probability of having an 
unrecoverable read error among all the drives at recover time starts 
becoming significant.  Sure, you can use it - as long as a restore from 
tape, etc. is an acceptable fallback if you can't rebuild after a drive 
replacement.