qemu-img command-line utility and optionally virt-manager for a graphical interface. Guest Software Packages
To increase the disk size to 80GB:
Unlike ISO installations, deploying from a pre-configured windows 8.1 qcow2 image saves you from the tedious 30-minute setup process. However, finding a proper guide that bridges the gap between a raw ISO and a functional QCOW2 image is rare.
Look for items marked with a yellow exclamation mark (such as Ethernet Controller , PCI Simple Communications Controller , and System Devices ). windows 81 qcow2 install
Open your terminal and run the following command to create a 40 GB virtual disk: qemu-img create -f qcow2 windows81.qcow2 40G Use code with caution. -f qcow2 : Specifies the target disk format. windows81.qcow2 : The filename of your virtual disk. 40G : The maximum storage capacity allocated for the drive. Step 2: Launch the QEMU/KVM Virtual Machine
: Since Microsoft officially ended support in January 2023, downloading it from the official site can be tricky. You may need to source it from the Internet Archive or use a physical disc.
qemu-img convert -f vmdk -O qcow2 windows81.vmdk windows81.qcow2 Use code with caution. Look for items marked with a yellow exclamation
virsh domblklist win81 # Find disk target (e.g., vda) virsh snapshot-create --disk-only --atomic win81 cp /var/lib/libvirt/images/windows81.qcow2 /backup/windows81_backup.qcow2 virsh blockcommit win81 vda --active --verbose --pivot
qemu-img create -f qcow2 /var/lib/libvirt/images/win8.1.qcow2 60G
Select and point it to your Windows 8.1 ISO. windows81
Because Windows 8.1 does not include native VirtIO drivers, the installer will initially report that "no drives were found".
For better management in Proxmox or KVM, install the guest agent from the VirtIO disk.
qemu-img resize windows81.qcow2 +40G
While Microsoft officially ended support for Windows 8.1 on January 10, 2023 , QCOW2 remains a highly efficient format because it only uses disk space as it’s needed. 1. Prerequisites Before starting, ensure you have: The official installation media. QEMU/KVM Installed: A functional virtualization stack.
| Problem | Solution | |---------|----------| | Windows setup cannot see QCOW2 disk | Load viostor driver from VirtIO ISO during install. | | Blue screen INACCESSIBLE_BOOT_DEVICE after install | Boot from Windows recovery → command line: sc config viostor start= boot . Or reinstall with correct driver loaded before first boot. | | Slow disk I/O despite VirtIO | Ensure cache=none or writeback on QEMU command line. On Proxmox, set and Discard option. | | Network driver missing | Install netkvm from VirtIO ISO → Device Manager → update driver for Ethernet Controller. | | QCOW2 snapshot causes BSOD | Windows 8.1 doesn’t always handle live snapshots well. Use qemu-ga and quiesce before snapshot. | | Windows 8.1 won't boot after qemu-img resize | Extend partition using Disk Management inside the VM (after resizing QCOW2). |