On 14/10/13 09:06, Mark Rogers wrote:
For me, the I=Inexpensive bit matters, because it's about saying "buy cheap disks, expect them to fail, build in redundancy so it doesn't matter when they do". Expecting the disks to fail is important, because then the redyundancy is taken seriously - it's not just "a nice to have it just in case but as it'll never happen I won't check it's set up correctly".
If I could, I would buy disks at half the price that failed twice as often and rotate them more frequently. Although in that case I don't think I'd consider RAID5 to be a sufficient level of redundancy.
Funny, I'd rather have the opposite, even with redundancy in my array. :D
Unfortunately because drive sizes have increased faster than the uncorrected read error rate, the statistical likelihood of recovering completely from a failed drive when you have member sizes of say 2TB is now so low there is almost no point counting RAID 5 as fault tolerant.