Remember: QCOW2’s snapshot feature is your best friend. Before installing that obscure 2009 accounting software or testing a USB driver from an untrusted source, take a snapshot. One command ( virsh snapshot-revert ) rolls back any disaster in seconds.
qemu-img convert -f vhdx -O qcow2 windows7-source.vhdx windows7-fresh.qcow2 Out of the box, Windows 7 in KVM can feel sluggish. Apply these tweaks: 1. Enable VirtIO-Balloon (Memory Overcommit) virsh edit windows7 Add (or ensure present): windows 7 qcow2 image install download
| Feature | QCOW2 | RAW | VHDX (Hyper-V) | |---------|-------|-----|----------------| | | ✅ Native (instant) | ❌ Requires external tools | ✅ Limited | | Compression | ✅ Zlib (saves 30-60% space) | ❌ | ❌ | | Encryption | ✅ AES-256 | ❌ | ✅ | | Performance | Near-native with caching | Best (but no features) | Good | | Sparse files | ✅ Automatic | ❌ (fixed size unless manually sparse) | ✅ | Remember: QCOW2’s snapshot feature is your best friend
qemu-img create -f qcow2 windows7.qcow2 40G Why 40GB? Windows 7 with updates and a few apps can easily exceed the official 16GB minimum. Sparse allocation means it uses only real space as needed. Windows 7 does not include VirtIO block or network drivers. Get the Fedora Project’s stable ISO: qemu-img convert -f vhdx -O qcow2 windows7-source