I'm setting up a new FreeBSD 10 system with four identical drives to be configured in a ZFS pool primarily used for network storage with CIFS clients. I want to make sure I'm putting together the best configuration. I'd like more fault tolerance than RAID-Z1 offers me, and I think RAID-Z3 is overkill. So I'm looking at either putting them all in a single RAID-Z2 vdev, or making two mirror vdevs of two drives each.
The total capacity should be comparable, so that's not really a factor. If I understand correctly, the RAID-Z2 configuration will give me more fault tolerance, because the zpool could survive the loss any two drives. Is that correct? Obviously with the mirrors, if two drives failed and they were from the same mirror, I'd be dead in the water.
While I'm not especially concerned about performance (most of the clients will be on WiFi, and I'd expect that to be the bottleneck), I also don't feel like I have a solid handle on the relative performance impacts of these configurations. Am I correct in my understanding that the mirrors will give better read performance? Read performance is more important than write performance for me, but fault tolerance trumps them both.
Is there anything else I need to consider?
The total capacity should be comparable, so that's not really a factor. If I understand correctly, the RAID-Z2 configuration will give me more fault tolerance, because the zpool could survive the loss any two drives. Is that correct? Obviously with the mirrors, if two drives failed and they were from the same mirror, I'd be dead in the water.
While I'm not especially concerned about performance (most of the clients will be on WiFi, and I'd expect that to be the bottleneck), I also don't feel like I have a solid handle on the relative performance impacts of these configurations. Am I correct in my understanding that the mirrors will give better read performance? Read performance is more important than write performance for me, but fault tolerance trumps them both.
Is there anything else I need to consider?