Reminder -- RAID 5 is not your friend

[richard.pieri-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Richard Pieri)]

On Mar 11, 2010, at 12:29 PM, Derek Atkins wrote:
> 
> In fact, if you lose the *right* set of disks you can lose 50% of your
> disks in RAID10 and still not lose your data.  :-D

I don't consider a 1 in 2 chance of data loss to be "reliable".

And technically, that chance decreases with the size of N.  With 20-disk RAID 1 or RAID 10 set (N=10), the chance of a second disk failure taking out the entire set is 1 in 10.  Meanwhile, the probability of the first failure in the set goes up with the number of disks in the set so it isn't a nice, simple line.

--Rich P.