diff --git a/README.md b/README.md
index 3763e19eef9cf6601663fd4ebe878b50d20438ff..e5f2cf3cb6e5c2f8aae23dd3106f23d7823b6b88 100644
--- a/README.md
+++ b/README.md
@@ -23,6 +23,11 @@ Acutally, this project does :
 	```shell
 	apt-get install sshpass
 	```
+	+ Configure ansible (allow becoming unprivileged user without error : "Failed to set permissions on the temporary files Ansible needs to create when becoming an unprivileged user")
+	```shell
+	sed -i 's/.*pipelining.*/pipelining = True/' /etc/ansible/ansible.cfg
+	sed -i 's/.*allow_world_readable_tmpfiles.*/allow_world_readable_tmpfiles = True/' /etc/ansible/ansible.cfg
+	```
 * Vagrant with virtualox
 	+ Install virtualbox on your own computer (for Ubuntu or Debian):
 	```
@@ -84,6 +89,12 @@ Inside this file, edit your network setting (name for your interface adaptator a
 	```shell
 	vim /etc/hosts
 	```	
+	if you did not edit your cluster settings since you git have pulled, you may want to use this default settings:
+	```shell
+	10.0.0.10 namenode
+	10.0.0.11 datanode1
+	10.0.0.12 datanode2
+	```	
 4. in cli : start your multiple VM from this [directory : vagrant/cluster](vagrant/cluster) :
 	```shell
 	vagrant up
diff --git a/playbook/roles/hadoop-common/tasks/main.yml b/playbook/roles/hadoop-common/tasks/main.yml
index 9c0afeeb2896c2d6b2c80cd4e974bbcec59e1005..be73f3e0c8717383cb5faa3354df75261333f47e 100644
--- a/playbook/roles/hadoop-common/tasks/main.yml
+++ b/playbook/roles/hadoop-common/tasks/main.yml
@@ -29,7 +29,7 @@
 
 - name: Set JAVA_HOME as environment variable
   become: yes
-  # become_user : hadoop
+  become_user : hadoop
   blockinfile:
     insertafter: EOF
     path : ~/.bashrc