prevent cannot chdir to /root error
diff --git a/xos/scripts/docker_start_xos b/xos/scripts/docker_start_xos
index 9e1ce6c..2ebd099 100755
--- a/xos/scripts/docker_start_xos
+++ b/xos/scripts/docker_start_xos
@@ -9,6 +9,7 @@
     done
 }
 
+cd /tmp
 service postgresql start
 wait_postgres
 service supervisor start