Best RAID for FreeNAS

[countach1]

Hey. New to FreeNAS and just had a couple of questions before I starting building.

I recently purchased 4x 2TB Seagate Iron Wolves (got a good deal on them) and was wanting to know what the best configuration would be. I want to have something for live data and backup as well. I've seen that RAIDZ2 is probably the best option to go with, but any input and feedback is appreciated.

 

[danb35]

RAIDZ2 is good, offers good redundancy, but you'll need to either add at least four more disks, or replace all four disks, to expand your pool, and it eats half of your total storage for redundancy. Mirrors offer less redundancy (if you lose the wrong two disks at the same time, you lose your pool), uses the same amount of space for redundancy, but can be expanded with only two disks, and resilvers will generally be faster. Kind of a toss up.

Or get two more disks and go for RAIDZ2.