Strongly recommend setting up a NAS device to store your media - it’ll stop you from having to migrate data and reconfigure Plex when your storage fills up. You can upgrade the storage whenever you need and mount it via NFS/SMB in Proxmox under Datacenter > Storage
You can even run the NAS in Proxmox if you feel froggy. Just make sure to connect all the drives directly to your VM instead of the Proxmox Host, and make sure it’s started BEFORE you try to run any other VMs because those shares won’t be available without that VM being on.
You might want the NAS on other hardware to avoid that, but that’s your decision.
Get in losers, we’re making a better world whether they want to help us or not