@T_Minus - your thread here has morphed all over the place. It is kind of a fun birdwalk to read through.
I don't think Owncloud/Nextcloud is going to do what you want. It is not a NAS management platform, but rather more of a storage upload/download & collaboration tool. While it is interesting when the application fits, in this case it is not going to be much help.
If I do understand your target application, what you want is a virtualization environment that has a full-service NAS capability as part of the virtualization host OS rather than a more "vanilla" virtualization host (like ESXi) that requires you to host your NAS as a VM, which implies a pass-through HBA requirement for performance and to give ZFS direct access to the disks. From your first post it is this pass-through HBA that you are trying to avoid.
This is a shared quest...AFAIK, there are only a few reasonable options:
- Proxmox. Upside is solid virtualization environment based on KVM, reasonable community support on their forums with active participation from the developers (who have recently figured out that insulting their user base on the forums is a bad idea). Downside is that there is no known management GUI for sharing as a NAS. You are pretty much down-and-dirty with the CLI. Note: this is the path I have chosen.
- FreeNAS. This is a story of frustration, with the "Corral" debacle still fresh in many peoples minds. While some may not like it, the NAS management tools of FreeNAS are quite good - excellent even. The promise of a virtualization management toolbox attached to FreeNAS was the major draw to Corral, and the heart of the letdown when they pulled it back. With FreeNAS 11.1's imminent release there is still hope here. But few people who committed to it and then had the rug pulled out with Corral are likely to try.
- Napp-It. Napp-It provides a really good NAS management tool suite for Solarish OSs (Solaris, Illuminos, etc.). There is good support for KVM-based virtualization here. But if you want the NAS as the VM-host you have the opposite problem from Proxmox. You'll be managing the VMs from the CLI (or an add-in KVM management suite). Choose your poison...
The other options people have suggested go downhill fast. For example, Xpenology could be fun, and might do what you want if you can limit your VM needs to those that can be hosted in Docker. But you'd tear your hair out pretty quickly trying to keep up with Xpenology's "quirks". Etc, etc. There are even variants using Hyper-V and Windows disk sharing - but i don't recommend going there anymore.
You could also go back to hybrids - FreeNAS or Napp-It under Proxmox or ESXi, but this is what you were trying to avoid.
Personally, after going after this nine ways to Sunday, I've just settled in on Proxmox + Docker/Portainer + CLI-based NAS services. Its really not that hard to manage the file sharing without the pretty GUI.
