diff --git a/lxc_backup.sh b/lxc_backup.sh
index 93db54f..c25f03a 100755
--- a/lxc_backup.sh
+++ b/lxc_backup.sh
@@ -20,10 +20,11 @@ then
 	exit 2
 fi
 
-for container in $(${lxccmd} list --format csv -c n | grep -v backup| grep -v "^oo" | grep -v test);
+#containder without an backup ends with -0
+for container in $(${lxccmd} list --format csv -c n | grep -v "-0$");
 do 
 	${lxccmd} copy ${container} ${container}-backup
-	${lxccmd} export ${container}-backup ${backuppath}$(date +%Y_%m_%d)-lxc-${container}.tar.gz
+	${lxccmd} export ${container}-backup ${backuppath}$(date +%Y_%m_%d)-lxc-${container}.tar.gz --instance-only --optimized-storage
 	${lxccmd} delete ${container}-backup
 done
 
@@ -31,4 +32,4 @@ done
 find ${backuppath} -mtime +28 -exec rm -f {} \;
 
 #own data for backupuser
-chown -R ${backupuser}:${backupuser} ${backuppath}
+chown -R ${backupuser}:${backupuser} ${backuppath}
\ No newline at end of file