hyper2kvm

Testing Converted Photon qcow2 on Fedora (GUI, BIOS)

This guide describes how to validate a converted Photon OS qcow2 image using KVM + libvirt on Fedora, booting directly into graphical (GUI) mode with legacy BIOS (SeaBIOS).

This is intended as a post-conversion smoke test after migrating a VMware VMDK to qcow2 and applying offline fixes (fstab, GRUB, initramfs, disk identifiers, etc.).

Prerequisites

Before migrating this platform, ensure:

Table of Contents

Host Requirements (Fedora)

Install required virtualization tools:

sudo dnf install -y \
  libvirt \
  qemu-kvm \
  qemu-img \
  virt-viewer \
  libguestfs-tools

Enable libvirt and ensure the default network is active:

sudo systemctl enable --now libvirtd
sudo virsh net-start default 2>/dev/null || true

Image Under Test (Photon OS)

/home/ssahani/by-path/out/photon.qcow2

Assumptions:

Important - Virtio Support:

Photon OS is a cloud-native distribution that ships with virtio drivers pre-installed in the initramfs. After conversion with hyper2kvm:

BIOS + GUI libvirt XML (Most Compatible)

This XML configuration is intentionally conservative and works reliably for Photon and other minimal Linux guests:

cat >/tmp/photon-test.xml <<'EOF'
<domain type='kvm'>
  <name>photon-gui</name>

  <memory unit='MiB'>4096</memory>
  <vcpu>2</vcpu>

  <os>
    <type arch='x86_64' machine='pc'>hvm</type>
    <boot dev='hd'/>
  </os>

  <features>
    <acpi/>
    <apic/>
  </features>

  <cpu mode='host-passthrough'/>

  <devices>
    <!-- Disk -->
    <disk type='file' device='disk'>
      <driver name='qemu' type='qcow2'/>
      <source file='/home/ssahani/by-path/out/photon.qcow2'/>
      <target dev='vda' bus='virtio'/>
    </disk>

    <!-- Network -->
    <interface type='network'>
      <source network='default'/>
      <model type='virtio'/>
    </interface>

    <!-- Graphics -->
    <graphics type='vnc' autoport='yes' listen='127.0.0.1'/>

    <!-- Video -->
    <video>
      <model type='vga'/>
    </video>

    <input type='tablet' bus='usb'/>
  </devices>
</domain>
EOF

Define and Start the VM

If a domain with the same name already exists, remove it first:

sudo virsh destroy photon-gui 2>/dev/null || true
sudo virsh undefine photon-gui 2>/dev/null || true

Define and start the VM:

sudo virsh define /tmp/photon-test.xml
sudo virsh start photon-gui

Connect to the Console / GUI

virt-viewer photon-gui

Option 2: VNC

sudo virsh vncdisplay photon-gui

Connect to the displayed address, for example:

127.0.0.1:5901

Expected Boot Sequence (Photon)

A successful boot typically shows:

  1. SeaBIOS splash
  2. GRUB (or Photon bootloader)
  3. Photon kernel + initramfs
  4. Login prompt (console or GUI, depending on image)

Important:
Photon OS is commonly console-only.
A login prompt is a successful boot.

Troubleshooting

Black screen after GRUB

Try an alternative video model:

<model type='qxl' vram='65536'/>

or:

<model type='virtio'/>

“No bootable device”

This is very rare with modern Photon OS. Photon ships with virtio drivers and should boot with virtio disk.

If you encounter this issue (unlikely with Photon OS 3.0+), try SATA as a fallback:

<target dev='sda' bus='sata'/>

Recommended approach:

  1. Always try virtio first (default configuration)
  2. Only use SATA if virtio fails (not expected for Photon OS)

Boots but no GUI

Photon OS does not install a graphical stack by default.

Inside the guest:

systemctl get-default

If it reports multi-user.target, this is expected behavior.

Initramfs rebuild warning during conversion

During hyper2kvm conversion, you may see:

⚠️  initramfs rebuild failed: mtime+size unchanged

This is normal and expected for Photon OS. It means:

Verification: After conversion, the VM should:

Notes

Status: Verified boot for Photon OS (BIOS, KVM/libvirt)

Next Steps

After migrating this platform:

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