u/Vesserik

Hardware:

• Dell PowerEdge R730 (Ubuntu 24.04) — 10× 1.2TB SAS
• Chenbro chassis (TrueNAS Scale) — 10× 3TB internal
• NetApp DS2246 — 24× 600GB SAS (connected to TrueNAS via LSI SAS9207-8e HBA)
• EMC JBOD — 24× 900GB SAS (daisy chained through DS2246)
• Incoming: NetApp DS4246 — 24× 4TB (will daisy chain into existing shelf chain)

Current setup: The R730 runs Ubuntu with a local ZFS pool (1.2TB drives). The Chenbro runs TrueNAS and manages everything else through the HBA and shelf chain. Both servers use MergerFS on the R730 to present a unified /data path to Plex and the arr stack. Downloads land on an Intel Optane P4800X as a scratch device, with an Oracle F80 as SLOG on the TrueNAS pool.

The question: With drives split across multiple shelves in four different sizes, what's the best ZFS pool architecture for Plex media storage?

Specifically I'm trying to figure out:

1. Should I run one big pool with lots of vdevs, or separate pools per drive size group?
2. Within each drive size group, should I split into multiple smaller vdevs or one wide vdev?
3. Is dRAID worth it here? The 24-drive groups seem like good dRAID candidates.
4. I keep hearing "if one vdev fails the whole pool is gone" does that change the calculus on how wide to make each vdev?

Primary use case is Plex streaming. TrueNAS box has 296GB ECC RAM for ARC.

Happy to hear any opinions on the architecture.