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🧪 Testing MOS in a Virtual Machine

MOS can be tested easily inside a virtual machine. This is useful for evaluation, development, or getting familiar with the WebUI before installing MOS on physical hardware.

note

MOS supports UEFI boot only by default. Legacy BIOS / CSM boot is not supported.

📦 VM Image​

mos_amd64.img.xz
  • Intended for virtual machines
  • Prebuilt disk image
  • No manual partitioning required

🧰 Preparing the VM Image​

Extract the image on Linux:

unxz --decompress mos_amd64.img.xz

This will produce:

mos_amd64.img

🖥️ Creating the Virtual Machine​

MOS works with common hypervisors such as:

  • KVM / QEMU
  • Proxmox
  • VMware
  • VirtualBox (UEFI must be enabled)
SettingValue
FirmwareUEFI
CPU4 cores or more
Memory8 GB recommended
NetworkBridged or NAT

🔌 Attaching the Image to the VM​

The extracted image must be attached as a USB device — not as a regular virtual hard disk. MOS expects the image to behave like a bootable USB stick.

HypervisorMethod
KVM / QEMUAttach the image as a USB storage device
VMware / VirtualBoxUse USB passthrough or raw image support with UEFI enabled
note

The image already contains everything needed to boot MOS.

🧱 Proxmox VE Configuration​

The following steps describe how to run the MOS test image inside Proxmox VE.

warning

MOS requires UEFI boot and Secure Boot must be disabled.

1️⃣ Create the VM​

Create a new VM with the following settings:

SettingValue
BIOSOVMF (UEFI)
DisplayVirtIO-GPU
Secure Boot❌ Disabled
Machineq35 (recommended)
DiskCan be empty

2️⃣ Disable Secure Boot​

Proxmox enables Secure Boot by default when using OVMF. You must disable it using one of the following methods:

Option A — Recommended

During VM creation, make sure "Pre-enrolled keys" is not checked.

Option B

If Secure Boot is still active after creation:

  1. Boot the VM
  2. Enter the UEFI Setup
  3. Disable Secure Boot
  4. Save and exit

3️⃣ Upload the MOS Image​

Upload mos_amd64.img to the Proxmox ISO storage:

/var/lib/vz/template/iso/

4️⃣ Move the Image​

From the Proxmox host shell:

cp /var/lib/vz/template/iso/mos_amd64.img /var/lib/vz/images/mos_amd64.img

5️⃣ Modify the VM Configuration​

Edit the VM config file:

nano /etc/pve/qemu-server/<vmid>.conf

Add the following lines:

usb0: spice,usb3=1
args: -drive file=/var/lib/vz/images/mos_amd64.img,format=raw,if=none,id=usbdisk -device usb-storage,drive=usbdisk
note

This attaches the MOS image as a USB storage device.

▶️ Start the VM​

Start the VM — MOS will boot automatically.

🚀 First Boot​

  1. Start the virtual machine and ensure it boots via UEFI
  2. MOS will boot automatically
  3. Obtain the IP address from the VM console or your DHCP server
  4. Open the MOS WebUI in your browser:
http://<mos-ip-address>

🖥️ Proxmox VE: Install MOS to Disk​

After testing MOS in the VM, you can install it to a virtual disk for persistent use on Proxmox VE.

1️⃣ Install MOS to Disk​

  1. In the MOS WebUI, navigate to System Settings → Update System
  2. Click Install to Disk
  3. Wait for the installation to complete
  4. Wait for the notification that it is safe to reboot

2️⃣ Shutdown the VM​

  1. Shutdown the VM from the Proxmox WebUI or via CLI: 
    qm shutdown <vmid>

3️⃣ Remove USB Configuration​

Remove or comment out the USB configuration lines from the VM config file:

nano /etc/pve/qemu-server/<vmid>.conf

Comment out or delete these lines:

# usb0: spice,usb3=1
# args: -drive file=/var/lib/vz/images/mos_amd64.img,format=raw,if=none,id=usbdisk -device usb-storage,drive=usbdisk

4️⃣ Edit Boot Order​

Edit the VM configuration to prioritize the boot disk:

  1. In Proxmox WebUI, go to your VM → Hardware
  2. Click Hard Disk and ensure the boot order is set correctly
  3. Or edit the config file directly: 
    nano /etc/pve/qemu-server/<vmid>.conf
    Add or modify the boot line: 
    boot: order=scsi0;ide2;net0

5️⃣ Ready to Use​

  1. Start the VM again
  2. MOS will now boot from the installed disk
  3. All configurations and data will persist across reboots

✅ What to Expect​

  • Full MOS WebUI available
  • Pools, Docker, LXC, and VM features can be explored

⚠️ Limitations in Virtual Machines​

  • Hardware-specific features may be unavailable
  • GPU or PCI passthrough depends on the hypervisor

🧪 Summary​

  • Use mos_amd64.img.xz to test MOS in a VM
  • Extract the image and attach it as a USB device
  • UEFI boot is mandatory — Secure Boot must be disabled

Parts of this documentation were created with the assistance of AI tools. All AI-generated content has undergone review, but it may still contain inaccuracies, omissions, or outdated information.