25.04-RC1 - Cannot Get Windows To Work

[A_Dude_In_Maryland]

Happy Monday all.

Was playing with RC1 over the weekend. Before I start opening bug reports, I want to try to do a little more root cause analysis myself.

So I have tried a couple different flavors of Windows. Admittedly mostly server variants (2022, 2025). I am looking at the Incus config that TrueNAS UI creates, and I see how it creates the NVMe drive, but Windows is not showing it.

From there, I have used Distrobuilder - still not sure if that’s working properly, but following other Incus guides. Still no drives being shown and Windows regardless of version is going right to the “search for drivers” wizard.

I have also physically plugged a USB with a CD emulator (IODD Drive) with the VirtIO ISO as well as dug into the Incus CLI to attach the CD as another device to the instance.

Just wondering if there’s something missing like a platform driver, or another piece of hardware that needs attached so Windows detects the “disk” so it can proceed with installation.

[neofusion]

Sounds like the issue described here:

Can't migrate VMs after update to 25.04

Thats because of virtio drivers. You need to set disk io.bus to nvme which doesnt need them. It isnt yet exposed in Beta UI. Currently only in nightly, wait for RC or do it yourself in shell.

[A_Dude_In_Maryland]

Thanks, unfortunately still can’t get it to work… I now have multiple ways to get the VirtIO ISO to attach which all work (the QEMU additional switch seems to be the best) but for whatever reason, Windows installer cannot detect the disk drive. What’s weirder is I can pop open DISKPART on command line in the installer and manipulate it, but that could be a red herring.

It’s Windows Server 2022 if that makes a difference - I was hoping it didn’t. Also tried the AHCI switch for QEMU with no luck.

At this point I may just have to wait for release and try again… Incus support is experimental after all.

[neofusion]

To confirm, you tried changing io.bus to nvme and alter the boot.priority?
The link I posted did not say to use virtio drivers.

[Foxtrot314]

Don’t use NVMe for the Windows installer ISO. It doesn’t work.

GUIDE: How to install/migrate Windows VM to Fangtooth/Incus using Virtio drivers

Here I present multiple ways how to get Windows working on new Incus based VMs in Fangtooth with Virtio devices and drivers. This applies for Fangtooth RC. First some basics. Incus based VM disks (root disk, custom zvol, mounted ISO file etc.) can be of different types based on io.bus setting inside Incus config. TrueNAS sets this by default as nvme. Other options are virtio-scsi or virtio-blk. We are only interested in either nvme or virtio-scsi. nvme is default in TrueNAS. In RC you can c…

[A_Dude_In_Maryland]

Thanks for jumping in @Foxtrot314 - the persistence made me want to try again. I don’t know if something config wise had a minor misspelling or something else, but starting clean seemed to do the trick.

Option 3 worked. Thank you both for the effort. Going to wipe it once more and try again to be certain.

Overall I am very impressed with Incus has to offer so far. Looking forward to more options and capabilities in the future, but most importantly the UI improvements to TrueNAS to help manage it.