Upload your windows81.qcow2 file to your Proxmox host using SFTP.
At this point, Windows may not detect your virtual disk because it lacks drivers for the VirtIO SCSI controller. This is normal and expected. windows 81 qcow2 install
A well-tuned Windows 8.1 on QCOW2 (with VirtIO) should achieve near‑bare‑metal disk speeds – over 1 GB/s sequential with NVMe backend and cache=none. Upload your windows81
qemu-system-x86_64 -enable-kvm -m 4096 -smp 4 \ -cpu host -vga qxl \ -drive file=windows81.qcow2,if=virtio,format=qcow2,index=0 \ -cdrom /path/to/windows81.iso \ -drive file=/path/to/virtio-win.iso,media=cdrom,index=2 \ -boot order=d Use code with caution. Breakdown of Critical Parameters: A well-tuned Windows 8
For QCOW2 images on SSDs, enable the discard option to pass TRIM commands from the guest to the host. This frees up space in the QCOW2 file when files are deleted in Windows, keeping the image file size efficient:
The 40G is thin provisioned; it will only consume as much space as Windows actually writes.