Description of problem:
=======================
while purging cluster failures have been observed for Task - 'check for anything running ceph' 


Version-Release number of selected component (if applicable):
==============================================================
ceph-ansible-1.0.5-24.el7scon.noarch
or
ceph-ansible-1.0.5-22.el7scon.noarch

How reproducible:
=================
always


Steps to Reproduce:
==================
1. created  cluster with one MON and 3 OSD node
2. Did some I/O using rgw and rados
3. purge cluster using below command:-


Actual results:
================

[root@magna044 ceph-ansible]# ansible-playbook purge-cluster.yml 



TASK: [check for anything running ceph] *************************************** 
<magna078> REMOTE_MODULE command ps awux | grep -v grep | grep -q -- ceph- #USE_SHELL
<magna084> REMOTE_MODULE command ps awux | grep -v grep | grep -q -- ceph- #USE_SHELL
<magna085> REMOTE_MODULE command ps awux | grep -v grep | grep -q -- ceph- #USE_SHELL
<magna090> REMOTE_MODULE command ps awux | grep -v grep | grep -q -- ceph- #USE_SHELL
failed: [magna090] => {"changed": true, "cmd": "ps awux | grep -v grep | grep -q -- ceph-", "delta": "0:00:00.017119", "end": "2016-07-11 02:23:16.142153", "failed": true, "failed_when_result": true, "rc": 0, "start": "2016-07-11 02:23:16.125034", "stdout_lines": [], "warnings": []}
stderr: grep: write error
changed: [magna078] => {"changed": true, "cmd": "ps awux | grep -v grep | grep -q -- ceph-", "delta": "0:00:00.016761", "end": "2016-07-11 02:23:16.142792", "failed": false, "failed_when_result": false, "rc": 1, "start": "2016-07-11 02:23:16.126031", "stderr": "", "stdout": "", "stdout_lines": [], "warnings": []}
failed: [magna084] => {"changed": true, "cmd": "ps awux | grep -v grep | grep -q -- ceph-", "delta": "0:00:00.017559", "end": "2016-07-11 02:23:16.145490", "failed": true, "failed_when_result": true, "rc": 0, "start": "2016-07-11 02:23:16.127931", "stdout_lines": [], "warnings": []}
stderr: grep: write error
failed: [magna085] => {"changed": true, "cmd": "ps awux | grep -v grep | grep -q -- ceph-", "delta": "0:00:00.017466", "end": "2016-07-11 02:23:16.147364", "failed": true, "failed_when_result": true, "rc": 0, "start": "2016-07-11 02:23:16.129898", "stdout_lines": [], "warnings": []}
stderr: grep: write error

Expected results:


Additional info: