The millionth RaidZ2 thread: multiple vdevs in a pool or multiple pools

[andyjay777]

I am struggling to decide how to complete my main storage pool. All files copied from old NAS and now I have 7 x 10TB drives that need a home,

Use case for the main storage pool
Storing videos for plex. 1-2 users at a time.
Files copied from PC with NVME SSD and 10GBe network card. Speed to copy semi-important, but I am not breaking my neck to saturate the 10Gbe connection.

Hardware
Xeon W-1370
Gigabyte W480 Vision W
64 Gb ECC
2 x LSi9207 HBAs
1 x Intel X540 NIC
Corsair RM1000x

Pool Setup
FastPool = mirrors of 2x2TB + 2X1TB Crucial MX (stores photo, documents, apps)
BigPool = Currently RaidZ2, vdev1 = 6x16TB Exos 54% full (the pool in question)

Option 1 - Large pool with 2 vdevs
RaidZ2, each vdev on separate HBA
vdev1 = 6x16TB Exos (new drives)
vdev2 = 6x10TB Ironwolf (4 year old drives)
Pros: one pool to manage, higher speed for one off transfers
Cons: upgrade of capacity (esp as 10TB drives as they reach end of life). Imbalance between vdev1 (already 54% full) and vdev2

Option 2 - 2 pools, 1 vdev each
RaidZ2, each vdev on separate HBA
Pool1/vdev1 = 6x16TB Exos (new drives)
Pool2vdev2 = 6x10TB Ironwolf (4 year old drives)
Pros: Upgrade path in future would be to export Pool 1, create a new pool with new HDDs (using HBA from Pool1), copy from Pool 2. Remove pool 2. Import Pool 1. Only need to copy from Pool 2 once. (I am not sure this is a real benefit, as the most likely upgrade will be progressive as 10TB drives fail).
Cons: multiple pools to manage capacity wise.

 

[sretalla]

Option 1 - Large pool with 2 vdevs

I would go with that... it's unlikely that you'll see much difference with option 2 and it's simpler to manage capacity within the same pool.