Selfhosted

So you mount the pool to each vm that needs the shared data? Afaik zfs is not made for concurrency

Sure, you can also do this. But why not make it available to your network in addition to Jellyfin? What if you have a TV that doesn't have access to the Jellyfin app? If it's a private ZFS pool not on the network you're fucked. If you share the media via a network share, you can always do any number of things to stream that media to your TV.

It gives you a ton more options up to and including just watching the media on your PC in your favorite media browser.

You can do a share any number of ways. I simply banked on the fact that anyone willing to ask the question likely doesn't know how to setup SMB shares without a GUI like TrueNAS.

TrueNAS is not absolutely required.

It just seems to be the favorite. Anything would work. OMV, EasyNAS, OpenFiler, Rockstor, even just base *nix with the appropriate packages and config.

I would separate the media and the Jellyfin image into different pools. Media would be a normal ZFS pool full of media files that gets mounted into any VM that needs it, like Jellyfin, sonarr, radarr, qbittorrent, etc. (preferably read-only mounted in Jellyfin if you’re going to expose Jellyfin to the internet).

You'd create a ZFS pool for your shares, then a TrueNAS VM which serves your ZFS pool as NAS. Then setup your Jellyfin VM using your NAS as storage for your libraries. Ends up looking like this: https://x0.at/Gbqm.png

Your media is accessible via the network from any device because they're SMB shares, and it works just fine in Jellyfin. If you only create a ZFS pool for Jellyfin, your media can then only be accessed through Jellyfin. It limits your future options.

If you want to share storage you need some way of doing that. Zfs is a good option for storage on vm-host level, but ist not designed for shared usage. Im not sure what you are after, but maybe you want zfs storage inside the vm for snapshots, dedup etc? Or maybe you want to share your media storage between vm’s? The first case you can use zfs inside your vm, it does not know or care about how its disks are stored or of they are a physical drive. For the second use-case you want some way to share drives, like smb, nfs etc. or a distributed filesystem if you really want to over complicate things. Truenas might be over overkill for sharing a few volumes, but you need something. I believe you can share zfs over nfs now but i have never used that outside of proxmox cluster storage

I use both debian on a vm with samba+nfs and a bare metal truenas for my needs. Find your needs and figure out what solves them

Truenas is completely unnecessary, it just brings overhead and complexity. You are good with your setup.

It's frankly exactly as complicated as his postulated setup, only provides more flexibility. It's the best outcome.

The easy option is run docker in a privileged LXC container, it's basically like running it directly on Proxmox and will have no permissions issues.

Then you'd have to share them back from the host to the guest using NFS or samba, and there's no reason to have them on the host. No, you're fine. That's what I would consider the right way to do it for what you describe as your purpose. Putting more layers in there isn't serving a useful purpose, which is why I say to not bother with a NAS to store them, if your primary use of them is via the Arr stack VM.