On 5/3/20 1:44 AM, Caveman Al Toraboran wrote:
[snip]... so, we get the following combinations of disk failures that, if happen, we won't lose any data:RAID0 ------^------ RAID1 RAID1 --^-- --^-- F . . . < cases with . F . . < single disk . . F . < failures . . . F < F . . F < cases with . F F . < two disk . F . F < failures F . F . < . F F . < this gives us 4+5=9 possible disk failure scenarious where we can survive it without any data loss.
Minor point - you have one duplicate line there ". f f ." which is the second and last line of the second group. No effect on anything else in the discussion.
Trying to help thinking about odd numbers of disks, if you are still allowing only one disk to fail, then you can think about mirroring half disks, so each disk has half of it mirrored to a different disk, instead of drives always being mirrored in pairs.
