What are the specific pros and cons, perhaps even conventions, of attaching a volume to a VM directly from a proxmox zfs pool VS mounting the volume through a file/block storage solution like TrueNAS (which is running inside a VM)?
I have a proxmox server with several VMs, one of them running TrueNAS and another running Linux with all my docker instances (others running various services)
The idea of running absolutely all file/block management for docker-centric VMs (and other files related to other VMs) through TrueNAS is appealing to me but I'm not entirely sure if this is just viewing everything as a nail with TrueNAS as the hammer. It's running on the same hardware, so really less of a concern than perhaps when running TrueNAS on dedicated hardware or even within a proxmox datacenter spread across several nodes.
The alternative is simply creating another hard disk from a zfs pool and attaching directly to a VM. Is this considered uncouth given the option to use TrueNAS?
I feel like migration would become less clean by attaching it directly and not taking advantage of TrueNAS, as from what I have learnt so far in this journey into server: as much persistent storage as can be possibly detached from the core running VM, should be.
EDIT: in the case of docker instances, this would not be storage for dependancy of service, rather storing things like user content and other non-ephemeral data.