For better performance on modern SSDs, add clustering:
qemu-system-x86_64 \ -m 4096 \ -cpu host \ -smp cores=4 \ -enable-kvm \ -drive file=win7.qcow2,if=virtio,driver=qcow2,cache=none \ -cdrom virtio-win-0.1.iso \ -net nic,model=virtio -net user windows 7 qcow2 top
qemu-img create -f qcow2 -o cluster_size=2M,backing_file=win7-base.qcow2,backing_fmt=qcow2 win7-overlay.qcow2 For better performance on modern SSDs, add clustering:
: During the "Where do you want to install Windows?" step, no drives will appear if you used if=virtio . Click Load Driver , browse the VirtIO CD, and select the viostor/w7 folder for your architecture (x86 or amd64). For better performance on modern SSDs
The -c flag enables compression. This can shrink a 100GB sparse image to 30-40GB without data loss.
echo 1024 > /proc/sys/vm/nr_hugepages # In VM XML: <memoryBacking> <hugepages/> </memoryBacking>