Migrate VM’s to Fangtooth and install Home Assistant through a ZVOL. Why keep the zvol?

[Gamy4]

When I migrate a VM from Electric Eel to Fangtooth I load the Zvol into a Instances Volume.
I was expecting to create a new instances where the zvol volume would be “consumed” into the new root disk.
However, the zvol is there to stay - uncoupling the zvol from the VM makes the VM unusable. It seems the new root disk is used for nothing…
Does anyone know/understand why?

Same for a Home Assistant new install. The only way to do it is to put Home assistant (the “evo” image) unto a new zvol, move/copy it to an Incas Volume and create a new VM with it. Also here the zvol needs to stay, and the root disk is for nothing.
Does anyone know/understand why?

[pmh]

Have not tried Incus yet, but aren’t virtual disk drives supposed to be in zvols? I have been using them that way in CORE for years - what could be better for a virtual disk than a virtual block device?

So I’m more curious about what these “root disks” might be?

[Stux]

@Gamy4

However, the zvol is there to stay - uncoupling the zvol from the VM makes the VM unusable. It seems the new root disk is used for nothing…
Does anyone know/understand why?

HOWTO: Replace an Incus VM root device with an external zvol

In Fangtooth 25.04 RC.1 you can create Incus VM Instances using external zvol. This is a good way to migrate an existing VM into the Incus system, but you will be left with a dangling “root” 10GiB volume attached to your VM. There is no harm in this, and it uses a trivial amount of space, but perhaps it annoys you and your would prefer to replace the root disk with the external zvol, and fully migrate your VM into the Incus ecosystem. WARNING: Incus 6.0.3 LTS is prone to erasing existing zvol…

[Gamy4]

I had seen there is this way to resolve it – it does annoy me a bit having this “dangling” root disk. But TrueNAS/Incus should actually arrange this and install the root disk from the zvol and make the zvol redundant. Just like creating a VM from any Linux iso. That would make better sense to me.