In the world of virtualization, the QCOW2 (QEMU Copy-On-Write version 2) format reigns supreme for its snapshot capabilities, thin provisioning, and efficient performance on KVM (Kernel-based Virtual Machine) and Proxmox environments. Pairing this with Windows 8.1—an operating system that still offers a unique balance between the traditional desktop paradigm and modern hardware support—creates a compelling use case for legacy software testing, industrial control systems, or simply running older peripherals.
: Hibernation creates a massive hiberfil.sys file that expands your QCOW2 image. Turn it off by opening Command Prompt as Administrator and running: powercfg -h off
When creating your QCOW2 image, use preallocation to improve performance:
virt-install \ --name win81 \ --ram 4096 \ --vcpus 2 \ --disk path=windows81.qcow2,format=qcow2 \ --cdrom /path/to/Windows_8.1.iso \ --disk path=virtio-win.iso,device=cdrom \ --os-variant win8.1 \ --graphics spice \ --network network=default,model=virtio windows 81 qcow2 install
Download the stable from the official Fedora repository.
qemu-img check -r all win81.qcow2 qemu-img convert -O qcow2 -c win81.qcow2 win81_compressed.qcow2 # compress
If you prefer a graphical interface:
When Windows setup starts and asks for a drive, you won't see any disk. Click Load Driver → Browse to the VirtIO CD drive → viostor\w8.1\amd64 → Next. The disk will appear. Proceed with normal installation.
QCOW2 is the native disk format for QEMU. It sits on top of your host file system (ext4, XFS, ZFS) and offers:
In this article, we've walked you through the process of installing Windows 8.1 on a virtual machine using QEMU and QCOW2. With these steps, you should now have a fully functional Windows 8.1 virtual machine up and running. Whether you're a developer, power user, or just someone who wants to try out a new operating system, this guide should help you get started with QEMU and QCOW2. In the world of virtualization, the QCOW2 (QEMU
sudo systemctl enable --now libvirtd sudo usermod -aG libvirt,kvm $USER
When the Windows 8.1 installer boots up, navigate through the initial language and region screens, click , and enter your product key.
X86_64 processor with hardware virtualization extensions (Intel VT-x or AMD-V) enabled in the BIOS/UEFI. Turn it off by opening Command Prompt as
: Essential for performance. Download the latest VirtIO-win ISO from the official Fedora/Red Hat repository .
Follow Proxmox Best Practices to enable "Write back" cache and "Discard" (TRIM) support for the best disk performance. 5. Troubleshooting Common Issues
