+guestfish

diff --git a/bin/qemu-img-recompress b/bin/qemu-img-recompress
index 0feb535..18f9a47 100755 (executable)
--- a/bin/qemu-img-recompress
+++ b/bin/qemu-img-recompress
@@ -12,6 +12,8 @@ for file in "$@";do
        set -xe
        mv -i "$file" "$file"-src
        rm -f "$file"-dest
+       test "$(guestfish -n -a "$file"-src run : list-devices : list-partitions|tr '\n' ' ')" = "/dev/vda /dev/vda1 "
+       guestfish -n -a "$file"-src run : zerofree /dev/vda1
        time qemu-img convert -c -f qcow2 "$file"-src -O qcow2 "$file"-dest
        mv -i "$file"-dest "$file"
        rm -f "$file"-src