I've been using unraid since 2010. Currently have a 32TB array (5x8TB with single parity) that is used for media and personal photo/video storage. I also have a 500GB appdrive outside the array. I'm running it on an old supermicro MB with an E5500 Pentium CPU. I'm currently running but it's 6.8.3. I am planning to migrate the array to some newer hardware (Xeon E3-1226 v3 w/16GB of RAM) and upgrade to unraid 7.2. I have some questions about how to configure my drives now that ZFS pools are available. I really have two objectives. First, I want a storage location that is both fault tolerant and also protected against bit rot. This would be used for personal photos/videos. The other objective is a storage location for media that is protected against drive failure and easily expandable as my media collection grows. Here's what I am thinking for my setup-

Unraid array - Single 8TB parity with some other random 2 & 3TB disks (these disks are all sitting idle now in a different test server)

ZFS pool - 4x8TB in RAID-z2. This would give me 16TB of useable space which is twice what I have allocated now to my photos/videos.

Appdrive - single NVME ~500G

Cache/downloads drive - single NVME >1TB

The combination of an unraid array for media with the RAID-z2 for my important stuff makes sense to me. I would use the UD plugin and external drives to backup the RAID-z2 content. No plan to backup the unraid array. I'd just have to rebuild my collection if I had multiple simultaneous drive failures on the unraid array. I don't run any VMs but do use Docker containers so I'd backup my appdrive to the unraid array. If the appdrive fails I replace it and restore it from backups on the array. If the cache drive fails I'd just have to replace whatever data was on it that hadn't moved to the array, not a big deal. The one downside to using the ZFS pool is I don't get the benefit of faster writes to a cache drive but I think I can live with that. I don't have a cache drive in my current setup so all my writes are not fast (30-35MB/s max IIRC).

Looking for feedback on this plan. Is there a better way to accomplish what I want? Specifically looking for feedback on if RAID-z2 is overkill and I should just go for RAID-z instead since I will have an offline backup and the chance of two simultaneous drive failures is relatively low. What kind of write performance can I expect from RAID-z2? Obviously it's hardware dependent but is it easy to at least match an unraid array or would it require beefier HW than I am planning?

Edited December 6, 2025Dec 6 by wsume99

The newer hardware is actually pretty old.

You’d better consider a raidz1 with an hot-spare if you’ve no other drives available. A raidz2 won’t let you more time and stress the drives harder regarding having only 4 drives.

For production, the array with a cache NVMe sounds good. Just think about a script to move your datas to your ZFS pool after some time if not done manually.

15 hours ago, wsume99 said:

What kind of write performance can I expect from RAID-z2? Obviously it's hardware dependent but is it easy to at least match an unraid array or would it require beefier HW than I am planning?

For large reads and writes, it should be a little slower than twice the speed of the disks used, say they are MR and can do around 200MB/s each; expect close to 400MB/s read as rights

With RAIDZ1, it would be closer to 600MB/s

On 12/6/2025 at 5:39 PM, gyto6 said:

The newer hardware is actually pretty old.

Yeah, I'm replacing ancient hardware with old hardware. I have been running the updated hardware in a test server and it's significantly more responsive than my existing server. Heck, a N150 would probably blow away my current hardware. I have the Xeon sitting around so figured I'd give it a try before buying anything new.