diff --git a/userdata/README.md b/userdata/README.md
index 2b04c16..0976dcb 100644
--- a/userdata/README.md
+++ b/userdata/README.md
@@ -1,8 +1,9 @@
 # Create jumps
 
 ```bash
+# NOTE(arnaud) we need large for the kubernetes ex.
 c=20
-openstack server create --user-data isen-postinstall.sh --min $c --max $c --flavor small --image 'Debian 12' --net public --key-name arnaud-choupinette isen
+openstack server create --user-data isen-postinstall.sh --min $c --max $c --flavor large --image 'Debian 12' --net public --key-name arnaud-choupinette isen
 ```
 
 # List jumps
diff --git a/userdata/isen-postinstall.sh b/userdata/isen-postinstall.sh
index b3c845f..d398819 100644
--- a/userdata/isen-postinstall.sh
+++ b/userdata/isen-postinstall.sh
@@ -105,7 +105,7 @@ add-apt-repository \
    stable"
 
 apt-get update
-apt-get install -y docker-ce docker-ce-cli containerd.io
+apt-get install -y docker-ce docker-ce-cli containerd.io fail2ban
 
 title.print "Clone trainings"