Greetings!
First, I originally posted this on Reddit (r/truenasscale) but it seems like it isn’t getting any traffic over there. I thought I would try here; this seems more appropriate anyway. Thanks!
So I’ve been putting off jumping on the TrueNAS/ZFS bandwagon for a while now because I never liked not being able to expand vdevs by adding drives. I didn’t like the idea of dropping a couple thousand dollars to add a whole new vdev to expand the pool. Ironically, now that vdev expansion has been added to ZFS (already? near future? …doesn’t matter anymore), I have enough drives, in the size I like, to build a zpool large enough to store all my data. So I thought I’d pop in and see what the community thinks of my plan (i.e., I’m seeking validation).
My current system is used purely as a NAS for media that I serve with Plex. Plex, and everything else (*arr apps), is on another system and runs in VMs. I currently use OMV in a VM with a 9361-8i raid controller passed through and a Raid6 6+2 with a hot spare; these are all 20TB Seagate Exos SATA drives. My server chassis is a 15-bay chassis and the filesystem is BTRFS. I hate the whole system…except the 15-bay chassis. BTRFS is not reliably available in OMV…at least for me.
My plan is to add a TrueNAS Scale VM and passthrough a 9300-16i SAS controller that I already have. I’ll build a zpool with one vdev of 7 drives in raidz2 (5+2) and I’ll migrate the data from OMV to TrueNAS Scale. Once that is done I’ll remove the drives from OMV and add them to TrueNAS Scale to make another vdev in the same zpool with 7 drives in raidz2 (5+2). I’ll have one drive left that I’ll use as a hot spare for the zpool. This TrueNAS Scale instance will serve as a NAS only and I will not be running VMs nor containers. It will serve my media library to Plex so my family in multiple locations can enjoy what I have. When I eventually need to expand I’ll go with another SAS controller, chassis and more vdevs of the same construction. I want one coherent filesystem that can grow at least twice more by adding vdevs after the migration is done. Memory for the TrueNAS VM will not be an issue as I have plenty.
Again, I won’t be moving Plex to TrueNAS no matter how many others do it that way; I like where I have it now. Also, I’m not keen on doing a bunch of 3-drive mirrors or other such expensive protection levels. Losing two drives out of seven to protection is about as costly as I’m willing to go. I would actually go wider if I had the drive bays and drives to create that first vdev so I can get everything moved from OMV to TrueNAS. In any case, keep in mind my chassis limitations. I will have seven drive bays available to get this started with the other eight becoming available after OMV is left empty.
So that’s it. Have at it! Please let me know if I’m on the right, or wrong, train of thought here. Thanks!
