Force usage of noop scheduler for virtual disks on Xen domUs

roles/common/tasks/base.yml

@@ -107,7 +107,6 @@
       - 10-disks.conf
   notify:
     - Refresh sysfs configuration
-  when: sysfs_disk_settings
 
 - name: Install sudo configuration
   template: src=sudo/local-admin.j2 dest=/etc/sudoers.d/local-admin owner=root group=root mode=0440

roles/common/templates/kernel/sysfs.d/10-disks.conf.j2

@@ -1,6 +1,11 @@
 #
 # sysfs: disk settings / tuning
 #
+{% if ansible_virtualization_type is defined and ansible_virtualization_type == 'xen' and ansible_virtualization_role == 'guest' %}
+{% for disk in ansible_devices %}
+block/{{ disk }}/queue/scheduler = noop
+{% endfor %}
+{% endif %}
 {% if sysfs_disk_settings %}
 {% for disk in ansible_devices -%}
 {% for key in sysfs_disk_settings %}