Not able to install talos in VM: "No disks matched for volume"

[mi-bauer]

As I was trying to reproduce another issue in a VM, I encountered a problem. Talos does not install itself on a virtual disk with the error log: "no disks matched for volume". I don't understand why this happens.

I used qemu and libvirt on ubuntu.
Steps to reproduce:

# using talos 1.10.6 from https://factory.talos.dev/?arch=amd64&cmdline-set=true&extensions=-&platform=metal&target=metal&version=1.10.6
wget https://factory.talos.dev/image/376567988ad370138ad8b2698212367b8edcb69b5fd68c80be1f2ec7d603b4ba/v1.10.6/metal-amd64.qcow2
sudo mv metal-amd64.qcow2 /var/lib/libvirt/images/talos-1.10.6-metal-amd64.qcow2


# setup the vm 
virt-install --connect qemu:///system \
--name talos-debug \
--os-variant linux2024 \
--memory 2048 \
--vcpus=2 --accelerate \
--graphics spice,keymap=de \
--disk /var/lib/libvirt/images/talos-1.10.6-metal-amd64.qcow2 \
--network=default \
--import

# generate a config
talosctl gen secrets
TARGET_IP=192.168.122.93 # pick the correct IP that is displayed on screen

talosctl gen config --with-secrets secrets.yaml talos-debug https://$TARGET_IP:6443
talosctl config merge ./talosconfig
talosctl config endpoint $TARGET_IP
talosctl config node $TARGET_IP

# merge the generated controlplane.yaml with a patch file. I used yq for that.
yq eval-all 'select(fileIndex == 0) * select(fileIndex == 1)' controlplane.yaml patch.yaml > controlplane-patched.yaml

# apply the config
talosctl apply-config --insecure --nodes $TARGET_IP --file controlplane-patched.yaml

This is the patch that I applied:

# patch.yaml
debug: true
machine:
  install:
    disk: /dev/vda

I get the error: "no disks matched for volume".

Before that upgrade that disk is visible:

talosctl -n ${TARGET_IP} -e ${TARGET_IP} get disks --insecure -o yaml
...
node:
metadata:
    namespace: runtime
    type: Disks.block.talos.dev
    id: vda
    version: 2
    owner: block.DisksController
    phase: running
    created: 2025-08-26T14:24:24Z
    updated: 2025-08-26T14:24:24Z
spec:
    dev_path: /dev/vda
    size: 2356150272
    pretty_size: 2.4 GB
    io_size: 512
    sector_size: 512
    readonly: false
    cdrom: false
    modalias: virtio:d00000002v00001AF4
    bus_path: /pci0000:00/0000:00:02.3/0000:04:00.0/virtio3
    sub_system: /sys/class/block
    transport: virtio
    rotational: true
    symlinks:
        - /dev/disk/by-diskseq/11
        - /dev/disk/by-path/pci-0000:04:00.0
        - /dev/disk/by-path/virtio-pci-0000:04:00.0

This is the talosctl version:

Client:
        Tag:         v1.10.6
        SHA:         cfa6c98c
        Built:
        Go version:  go1.24.5
        OS/Arch:     linux/amd64

As I provided the correct path I don't know what else could be the issue. Do you have any idea?

[smira]

First of all, remove debug: true, otherwise you might hit unrelated issues. You almost never need it, use talosctl support via talosconfig.

Second, there is no install process as you're booting from a disk image.

And third, make sure the disk is big enough -- your initial image doesn't contain extra space - 2.4 GiB is the initial boot image, Talos has nowhere to allocated EPHEMERAL.