Unwanted spindown on 2 out of 8 disks

[etorix]

@tokyo

I’m running TrueNAS Core TrueNAS-13.0-U6.2 in a Proxmox 8.2.7 VM on a Dell T320 with an HBA RAID controller in passthrough mode, which basically means that Proxmox doesn’t even know the disks are connected—only TrueNAS sees and manages them.

This, unfortunately, is not quite the case. See this thread

Can't import datapool

IIRC there is currently a bug / bad design decision in proxmox where it auto-imports zpools into the host OS. If the zpool is currently imported / in use in a guest as well this will cause pool corruption. ZFS is not a clustered filesystem and so it cannot be consumed by both host and guest simultaneously. IIRC the only way to avoid the data corruption is HBA passthrough. @HoneyBadger has more details.

and act accordingly to blacklist the HBA, disable Proxmox scanning, or moving TrueNAS bare metal. Also, it is really a “RAID controller”? Unrelated to your issue, this is not good either.

What's all the noise about HBAs, and why can't I use a RAID controller?