---
- name: test if grub configured for noop i/o scheduler
  command: egrep -q 'elevator=noop' /boot/grub2/grub.cfg
  register: grub
  changed_when: no
  failed_when: grub_test.rc == 2

- name: configure grub for noop i/o scheduler
  sudo: yes
  command: grubby --update-kernel=ALL --args=elevator=noop
  when: grub_test.rc == 1

- name: get list of block devices to test
  shell: ls /sys/block/ | egrep '^([shv]|xv])d[a-z]$'
  register: block_devs
  changed_when: no

- name: test if block device using noop i/o scheduler
  shell: cat /sys/block/{{ item }}/queue/scheduler | egrep -q '\[noop\]'
  with_items: block_devs.stdout
  register: noop_test
  changed_when: noop_test.rc == 1
  failed_when: noop_test.rc == 2

- name: set block device to use noop i/o scheduler
  sudo: yes
  shell: echo noop > /sys/block/{{ item }}/queue/scheduler
  with_items: block_devs.stdout
  when: noop_test.changed