Mirrors are generally better because you get shorter resilver times and you don't stress all the disks in your pool when you resilver (which is why a lot of dis

Mirrors are generally better because you get shorter resilver times and you don't stress all the disks in your pool when you resilver (which is why a lot of disk failures happen during RAID5 rebuilds -- the rest of the pool's disks are old). The downside is that it uses more disks for the same level of redundancy. I would also mention it's probably a good idea to use something like ZFS rather than a hardware RAID card. In general, free software RAID is better audited and you don't need specific hardware for the recovery process. But also, ZFS has proper checksumming, so you won't have to worry about all sorts of silent corruption (which RAID blissfully ignores -- most implementations will just recompute the parity in case of a mismatch, which is the wrong thing to do (1-1/n) of the time).