diff --git a/src/datastore_mad/remotes/libfs.sh b/src/datastore_mad/remotes/libfs.sh
index e890d94996..373774092e 100644
--- a/src/datastore_mad/remotes/libfs.sh
+++ b/src/datastore_mad/remotes/libfs.sh
@@ -178,11 +178,14 @@ function fs_size {
             SIZE=`du -sb "$1" | cut -f1`
             error=$?
         else
-            TYPE=$(cat "$1" | head -n 1024 | file -b --mime-type -)
+            TYPE=$(cat "$1" | head -n 1024 | file -b -)
             case "$TYPE" in
-            "application/x-gzip")
+            *gzip*)
                 SIZE=$(gzip_file_size "$1")
                 ;;
+            *QCOW*)
+                SIZE=$($QEMU_IMG info "$1" | sed -n 's/.*(\([0-9]*\) bytes).*/\1/p')
+                ;;
             *)
                 SIZE=$(file_size "$1")
                 ;;