diff --git a/prep-headnode-playbook.yml b/prep-headnode-playbook.yml
index 04c0c07..a49d2ae 100644
--- a/prep-headnode-playbook.yml
+++ b/prep-headnode-playbook.yml
@@ -66,3 +66,8 @@
   roles:
     - apache-proxy
 
+- name: Sysctl defaults
+  hosts: head
+  become: yes
+  roles:
+    - sysctl
diff --git a/roles/sysctl/tasks/main.yml b/roles/sysctl/tasks/main.yml
new file mode 100644
index 0000000..55ca7e4
--- /dev/null
+++ b/roles/sysctl/tasks/main.yml
@@ -0,0 +1,25 @@
+
+# Copyright 2017-present Open Networking Foundation
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+---
+# sysctl/tasks/main.yml
+
+- name: ElasticSearch mmap limit
+  sysctl:
+    name: vm.max_map_count
+    value: 262144
+    state: present
+    reload: yes