Windows 10qcow2 !!better!! Jun 2026

qemu-img convert -f vdi -O qcow2 source_disk.vdi target_disk.qcow2 Use code with caution.

Ensure your hypervisor's CPU setting is switched to host . If you migrated from an IDE/SATA setup to VirtIO, you must revert the bus type, install the VirtIO drivers inside Windows first, and then switch back. 2. Ballooning File Size on the Host File System

qemu-img create -f qcow2 windows10.qcow2 80G windows 10qcow2

With your disk image created and prerequisites in place, you can now start the VM and install Windows. You can use virt-manager for a graphical experience or use the command line for more control.

To reclaim empty space and compress the file, execute a shrinking procedure: qemu-img convert -f vdi -O qcow2 source_disk

Install the Guest Agent executable found on the VirtIO ISO. This ensures graceful shutdowns and accurate resource monitoring from the host panel. Converting Existing Images to QCOW2

# Power down the VM safely prior to maintenance qemu-img convert -O qcow2 -c win10.qcow2 compressed_win10.qcow2 Use code with caution. To reclaim empty space and compress the file,

Inside Windows 10, optimize and trim the drive, or run a zero-fill tool like Sysinternals SDelete ( sdelete64.exe -z c: ). Shut down the virtual machine completely. Run the host-side compression command:

qemu-img convert -f vhdx -O qcow2 source.vhdx target.qcow2

Navigate to the secondary CD-ROM drive containing the VirtIO files.

Virtualization is a cornerstone of modern IT infrastructure, development, and testing. When running Windows 10 inside a Kernel-based Virtual Machine (KVM) environment—such as Proxmox VE, QEMU, or OpenStack—the choice of virtual disk format dictates your entire experience.