Run the following command to start the installation process:
1. Click on "Load driver" at the bottom left of the window. 2. Click "Browse" and navigate to the mounted VirtIO CD-ROM drive. 3. Expand the directory: `viostor` -> `w10` -> `amd64`. 4. Select the VirtIO SCSI controller driver and click Next. 5. Your QCOW2 disk will now magically appear. Proceed with the installation normally. Use code with caution.
Use scripts like Windows 10 Debloater to remove background processes that eat up CPU cycles in virtual environments.
Check the box for "Customize configuration before install" before clicking Finish. Step 5: Inject VirtIO Drivers During Setup windows 10qcow2
| Device | Driver path on ISO | | :--- | :--- | | Disk controller | viostor\w10\amd64 | | Network | NetKVM\w10\amd64 | | Balloon (memory) | Balloon\w10\amd64 | | QEMU Guest Agent | guest-agent\qemu-ga-x86_64.msi |
Note: This creates a 60 GB virtual drive named win10.qcow2 . It will occupy less than a few megabytes on your host drive until Windows is installed. Step 4: Boot the VM and Install Windows 10
It grows only as you add data to the Windows 10 VM, saving significant storage space. Run the following command to start the installation
QCOW2 is the native disk image format for QEMU and KVM. Unlike standard raw images that allocate the entire disk space immediately, QCOW2 uses a dynamic allocation strategy. Key Features of QCOW2
After installing updates, the QCOW2 image may be bloated. On the host, use this command to reclaim space: qemu-img convert -O qcow2 win10.qcow2 win10-compact.qcow2 Use code with caution. Phase 4: Advanced QCOW2 Management Creating Snapshots qemu-img snapshot -c snapshot1 win10.qcow2 Use code with caution. Reverting Snapshots qemu-img snapshot -a snapshot1 win10.qcow2 Use code with caution. Linking Images (Backing Files) Create a new VM using the original as a read-only base: qemu-img create -f qcow2 -b win10.qcow2 new-vm.qcow2 Use code with caution. Summary Checklist for Windows 10 QCOW2 Best Practice QCOW2 (with preallocation=metadata ) Driver Type VirtIO (SCSI for disk, NetKVM for net) Compact Option Run qemu-img convert to shrink size Snapshots Use internal QCOW2 snapshots
During Windows Setup, when it asks where to install, click "Load Driver" and navigate to the virtio folder (e.g., viostor/w10/amd64 ). 5. Converting Existing Windows Images to qcow2 Click "Browse" and navigate to the mounted VirtIO
| Workload | QCOW2 vs RAW | Notes | | :--- | :--- | :--- | | Sequential read | 90–95% | Overhead minimal | | Sequential write | 85–90% | COW metadata update | | 4K random read | 85–95% | Depends on cache | | 4K random write | 60–80% | Highest overhead | | Boot time (NVMe) | +5–10 seconds | VirtIO + QCOW2 overhead |
Never use "IDE" or "SATA" emulation. Always set your disk bus to VirtIO for the fastest I/O speeds.
: Standard Windows installers do not include drivers for high-performance QEMU hardware. Download the latest virtio-win.iso from the Fedora project to ensure Windows can recognize the QCOW2 disk during setup. 3. Launch the Installation VM