

Edit: Also yeah you should be able to dual-boot but I wouldn’t recommend it. Linux and Windows bootloaders don’t like to play nice with eachother. 2nd Edit: Added the official PVE Hyper-V migration documentation, but that blog covers it in more detail.
You should be able to migrate most or all of your existing Hyper-V VMs to Proxmox, which would be relatively straight forward. My recommendation would be backing up everything to your TrueNAS (that has the dedicated HBA) then you can wipe your Windows boot drive and install Proxmox. Then you could start by migrating your TrueNAS VM over and passing it’s HBA back to it.
Once you have your NAS working in PVE then you could either migrate/rebuild your other VMs, or look into splitting your services into containers (Proxmox uses LXC natively, but Docker is another option.) There are some great helper scripts to get services spun up quickly so you can minimize downtime.
You didn’t mention how much, if any, experience you have with PVE/Debian and I know from a friend recently switching that some things are a bit more “difficult” than TrueNAS so hit me up if you need anything. The PVE admin documents will be helpful as well.
https://pve.proxmox.com/wiki/Advanced_Migration_Techniques_to_Proxmox_VE#HyperV








Yes, you can. https://pve.proxmox.com/wiki/Advanced_Migration_Techniques_to_Proxmox_VE#HyperV