diff --git a/root/scripts/backup.sh b/root/scripts/backup.sh
index 04982be..550d42b 100644
--- a/root/scripts/backup.sh
+++ b/root/scripts/backup.sh
@@ -144,6 +144,15 @@ function checkExist {
             # not found
             return 1
         fi
+    elif [ "$1" = "fs" ]; then
+        # find file > 0 bytes
+        if [ -s "$2" ]; then
+            # found
+            return 0
+        else
+            # not found
+            return 1
+        fi
     elif [ "$1" = "fd" ]; then
         # find directory
         if [ -d "$2" ]; then