semantic: 0.669
device: 0.655
other: 0.576
graphic: 0.355
network: 0.348
performance: 0.313
PID: 0.301
boot: 0.258
vnc: 0.210
socket: 0.205
debug: 0.182
KVM: 0.154
permissions: 0.099
files: 0.029

rename snapshot by qemu-img
Additional information:
I have no idea to rename a snapshot which created by `qemu-img snapshot -c`, I think it is a useful function