On Thu, Nov 10, 2022 at 08:32:36PM -0500, Dan Ritter wrote:
* RAID 5 and 6 restoration incurs additional stress on the other disks in the RAID which makes it more likely that one of them will fail.
I believe that's mostly apocryphal; I haven't seen science backing that up, and it hasn't been my experience either.
The advantage of RAID 6 is that it can then recover from that...
The advantage to RAID 6 is that it can tolerate a double disk failure. With RAID 1 you need 3x your effective capacity to achieve that and even though storage has gotten cheaper, it hasn't gotten that cheap. (e.g., an 8 disk RAID 6 has the same fault tolerance as an 18 disk RAID 1 of equivalent capacity, ignoring pointless quibbling over probabilities.)