At the moment I have my NAS setup as a Proxmox VM with a hardware RAID card handling 6 2TB disks. My VMs are running on NVMEs with the NAS VM handling the data storage with the RAIDed volume passed through to the VM direct in Proxmox. I am running it as a large ext4 partition. Mostly photos, personal docs and a few films. Only I really use it. My desktop and laptop mount it over NFS. I have restic backups running weekly to two external HDDs. It all works pretty well and has for years.
I am now getting ZFS curious. I know I’ll need to IT flash the HBA, or get another. I’m guessing it’s best to create the zpool in Proxmox and pass that through to the NAS VM? Or would it be better to pass the individual disks through to the VM and manage the zpool from there?
Why LVM + BTRFS instead of only using btrfs? Unless you need RAID 5/6, which doesn’t work well on btrfs.
Yes. Because they’re already using some sort of parity RAID so I assume they’d use RAID in ZFS/Btrfs and as you said, that’s not an option for Btrfs. So LVMRAID + Btrfs is the alternative. LVMRAID because it’s simpler to use than mdraid + LVM and the implementation is still mdraid under the covers.