I’m new to ZFS, and I’m planning my ZFS array and would love to hear your thoughts.
This server will be deployed at my parent’s place, and used mostly as backup of my home server, being that I live far, having the least amount of maintenance/greater redundancy would nice. I also will run a single game server, which will mostly hit the 100gb ram ARC I believe, so I’m most interested in reliability and performance, being fine with losing the bulk storage.
I’m planning it to have 6 2TB-ST2000NM000A, and looking at my options, I’m divided between:
RAIDZ2 of 6 drives, seem to be the most reliable but lest performant option.
2 vdevs comprised each of 3x raidz1 disks. From what I’ve read, it’s the best option for performance and reliability
Are those the best options for my setup? I’ve also read that I could make 3x mirrored vdevs of 2 disks each, but this seems prone to failure in case of a rebuild.
I’ve also read that I could make 3x mirrored vdevs of 2 disks each, but this seems prone to failure in case of a rebuild.
It’s certainly less prone to failure than a pair of RAIDz1 vdevs.
I almost always recommend mirrors. In your particular case, I recommend them because of the following line:
being that I live far, having the least amount of maintenance/greater redundancy would nice.
Mirrors sit in the middle between your proposed single RAIDz2 and double RAIDz1 when it comes to redundancy. But when it comes to decreasing maintenance hassles, you can’t beat them. Replacement disks resilver in massively more quickly than they do in RAIDz arrays, which means less flop-sweat when a drive fails AND less pain in the ass if you want to upgrade disk sizes down the road.
With a pair of RAIDz1 vdevs, you’d need to resilver in three new larger-capacity disks before seeing any increase in experienced capacity… and they’d be considerably slower resilvers than the pair of them necessary before experiencing expanded capacity with mirrors. If you went RAIDz2, you’d have to replace and resilver all six drives individually before seeing any additional capacity!
Similarly, if you have open bays available, mirrors make utilizing them much easier. Let’s say your server has eight bays, six of which you’re populating initially. The remaining two bays isn’t enough for another 3-wide Z1, let alone another six-wide Z2… but it’ll fit a new mirror vdev just fine. And that mirror vdev doesn’t need to be the same size as the others, either—say you originally used 8T drives, but 20T drives are the bang for the buck when you want to expand. Add your pair of new 20Ts, immediately see 20T additional capacity!
This is likely to become important pretty rapidly, given that you’re starting out with six 2T drives. I assume those are older drives, so between the low capacity and the age, you’re liable to need to start replacing them for one reason or another more quickly than you might be thinking.