Compress the Vagrant qemu image

build-inside-vm.sh

@@ -185,7 +185,7 @@ EOF
   local virtual_size
   virtual_size="$(grep -o "^[0-9]*" <<<"${DISK_SIZE}")"
   echo '{"format":"qcow2","provider":"libvirt","virtual_size":'"${virtual_size}"'}' >metadata.json
-  qemu-img convert -f raw -O qcow2 "${1}" box.img
+  qemu-img convert -c -f raw -O qcow2 "${1}" box.img
   rm "${1}"
 
   tar -czf "${2}" Vagrantfile metadata.json box.img