Ability to disable swap

With enough memory we will probably not need any swap.

Signed-off-by: Sébastien Han <sebastien.han@enovance.com>

roles/ceph-common/defaults/main.yml

@@ -124,6 +124,7 @@ radosgw: false # referenced in monitor role too.
 ###########
 
 disable_transparent_hugepage: true
+disable_swap: true
 os_tuning_params:
   - { name: kernel.pid_max, value: 4194303 }
   - { name: fs.file-max, value: 26234859 }

roles/ceph-common/tasks/os_tuning.yml

@@ -5,8 +5,13 @@
 
 - name: Disable transparent hugepage
   command: "echo never > /sys/kernel/mm/transparent_hugepage/enabled"
-  ignore_errors: true
   when: disable_transparent_hugepage
+  ignore_errors: true
+
+- name: Disable swap
+  command: swapoff -a
+  when: disable_swap
+  ignore_errors: true
 
 - name: Apply OS tuning
   sysctl: >