6 is preferable over 5 because with today’s disk sizes, swapping in a new drive and resilvering it (full disk write basically in terms of amount of data) takes so long that statistically you might just encounter a second failure during that, which for raid 5 would mean complete failure of the array.
Of course, that’s just an uptime issue, since raid is not backup.
what’s the advantage of raid 5&6 over something like raid 4&5 - it reads essentially the same to me - a parity redundancy.
6 is preferable over 5 because with today’s disk sizes, swapping in a new drive and resilvering it (full disk write basically in terms of amount of data) takes so long that statistically you might just encounter a second failure during that, which for raid 5 would mean complete failure of the array.
Of course, that’s just an uptime issue, since raid is not backup.
4 is bad because parity is on one drive so no matter what happens that drive is the write bottleneck. Raid5 is basically raid4 + raid0.
5 is just fine but low safety, I run 6 always and it has basically never let me down.