Description of problem:

During installation testing, I created a two node cluster using the default values. It gave me an error: 

[root@rhel-mon ~]# ceph health detail
HEALTH_WARN Reduced data availability: 32 pgs inactive; Degraded data redundancy: 32 pgs unclean; too few PGs per OSD (16 < min 30)
PG_AVAILABILITY Reduced data availability: 32 pgs inactive

I realized the default size was 3, so I wasn't going to get to a clean result. So I decided to purge my cluster with '# ansible-playbook purge-cluster.yml', which purged the cluster. Then, I re-ran '# ansible-playbook site.yml' after overriding the default pool size to 2. I got the following result. 

failed: [rhel-osd1] (item=[{'_ansible_parsed': True, 'stderr_lines': [], '_ansible_item_result': True, u'end': u'2017-09-15 14:05:51.609473', '_ansible_no_log': False, u'stdout': u'', u'cmd': u"parted --script /dev/sdb print | egrep -sq '^ 1.*ceph'", u'rc': 1, 'item': [{'_ansible_parsed': True, 'stderr_lines': [], '_ansible_item_result': True, u'end': u'2017-09-15 14:05:49.853054', '_ansible_no_log': False, u'stdout': u'', u'cmd': u"readlink -f /dev/sdb | egrep '/dev/([hsv]d[a-z]{1,2}|cciss/c[0-9]d[0-9]p|nvme[0-9]n[0-9]p)[0-9]{1,2}|fio[a-z]{1,2}[0-9]{1,2}$'", u'rc': 1, 'item': u'/dev/sdb', u'delta': u'0:00:00.009494', u'stderr': u'', u'changed': False, u'invocation': {u'module_args': {u'warn': True, u'executable': None, u'_uses_shell': True, u'_raw_params': u"readlink -f /dev/sdb | egrep '/dev/([hsv]d[a-z]{1,2}|cciss/c[0-9]d[0-9]p|nvme[0-9]n[0-9]p)[0-9]{1,2}|fio[a-z]{1,2}[0-9]{1,2}$'", u'removes': None, u'creates': None, u'chdir': None}}, 'stdout_lines': [], 'failed_when_result': False, u'start': u'2017-09-15 14:05:49.843560', 'failed': False}, u'/dev/sdb'], u'delta': u'0:00:00.020079', u'stderr': u'', u'changed': False, u'invocation': {u'module_args': {u'warn': True, u'executable': None, u'_uses_shell': True, u'_raw_params': u"parted --script /dev/sdb print | egrep -sq '^ 1.*ceph'", u'removes': None, u'creates': None, u'chdir': None}}, 'stdout_lines': [], 'failed_when_result': False, u'start': u'2017-09-15 14:05:51.589394', 'failed': False}, {'_ansible_parsed': True, 'stderr_lines': [], '_ansible_item_result': True, u'end': u'2017-09-15 14:05:49.853054', '_ansible_no_log': False, u'stdout': u'', u'cmd': u"readlink -f /dev/sdb | egrep '/dev/([hsv]d[a-z]{1,2}|cciss/c[0-9]d[0-9]p|nvme[0-9]n[0-9]p)[0-9]{1,2}|fio[a-z]{1,2}[0-9]{1,2}$'", u'rc': 1, 'item': u'/dev/sdb', u'delta': u'0:00:00.009494', u'stderr': u'', u'changed': False, u'invocation': {u'module_args': {u'warn': True, u'executable': None, u'_uses_shell': True, u'_raw_params': u"readlink -f /dev/sdb | egrep '/dev/([hsv]d[a-z]{1,2}|cciss/c[0-9]d[0-9]p|nvme[0-9]n[0-9]p)[0-9]{1,2}|fio[a-z]{1,2}[0-9]{1,2}$'", u'removes': None, u'creates': None, u'chdir': None}}, 'stdout_lines': [], 'failed_when_result': False, u'start': u'2017-09-15 14:05:49.843560', 'failed': False}, u'/dev/sdb']) => {"changed": true, "cmd": ["ceph-disk", "prepare", "--cluster", "ceph", "--filestore", "/dev/sdb"], "delta": "0:00:00.366718", "end": "2017-09-15 14:05:53.415466", "failed": true, "item": [{"_ansible_item_result": true, "_ansible_no_log": false, "_ansible_parsed": true, "changed": false, "cmd": "parted --script /dev/sdb print | egrep -sq '^ 1.*ceph'", "delta": "0:00:00.020079", "end": "2017-09-15 14:05:51.609473", "failed": false, "failed_when_result": false, "invocation": {"module_args": {"_raw_params": "parted --script /dev/sdb print | egrep -sq '^ 1.*ceph'", "_uses_shell": true, "chdir": null, "creates": null, "executable": null, "removes": null, "warn": true}}, "item": [{"_ansible_item_result": true, "_ansible_no_log": false, "_ansible_parsed": true, "changed": false, "cmd": "readlink -f /dev/sdb | egrep '/dev/([hsv]d[a-z]{1,2}|cciss/c[0-9]d[0-9]p|nvme[0-9]n[0-9]p)[0-9]{1,2}|fio[a-z]{1,2}[0-9]{1,2}$'", "delta": "0:00:00.009494", "end": "2017-09-15 14:05:49.853054", "failed": false, "failed_when_result": false, "invocation": {"module_args": {"_raw_params": "readlink -f /dev/sdb | egrep '/dev/([hsv]d[a-z]{1,2}|cciss/c[0-9]d[0-9]p|nvme[0-9]n[0-9]p)[0-9]{1,2}|fio[a-z]{1,2}[0-9]{1,2}$'", "_uses_shell": true, "chdir": null, "creates": null, "executable": null, "removes": null, "warn": true}}, "item": "/dev/sdb", "rc": 1, "start": "2017-09-15 14:05:49.843560", "stderr": "", "stderr_lines": [], "stdout": "", "stdout_lines": []}, "/dev/sdb"], "rc": 1, "start": "2017-09-15 14:05:51.589394", "stderr": "", "stderr_lines": [], "stdout": "", "stdout_lines": []}, {"_ansible_item_result": true, "_ansible_no_log": false, "_ansible_parsed": true, "changed": false, "cmd": "readlink -f /dev/sdb | egrep '/dev/([hsv]d[a-z]{1,2}|cciss/c[0-9]d[0-9]p|nvme[0-9]n[0-9]p)[0-9]{1,2}|fio[a-z]{1,2}[0-9]{1,2}$'", "delta": "0:00:00.009494", "end": "2017-09-15 14:05:49.853054", "failed": false, "failed_when_result": false, "invocation": {"module_args": {"_raw_params": "readlink -f /dev/sdb | egrep '/dev/([hsv]d[a-z]{1,2}|cciss/c[0-9]d[0-9]p|nvme[0-9]n[0-9]p)[0-9]{1,2}|fio[a-z]{1,2}[0-9]{1,2}$'", "_uses_shell": true, "chdir": null, "creates": null, "executable": null, "removes": null, "warn": true}}, "item": "/dev/sdb", "rc": 1, "start": "2017-09-15 14:05:49.843560", "stderr": "", "stderr_lines": [], "stdout": "", "stdout_lines": []}, "/dev/sdb"], "rc": 1, "start": "2017-09-15 14:05:53.048748", "stderr": "Could not create partition 2 from 10487808 to 20973567\nError encountered; not saving changes.\n'/sbin/sgdisk --new=2:0:+5120M --change-name=2:ceph journal --partition-guid=2:e4d6155e-224b-45e6-97fd-437b1c512dd8 --typecode=2:45b0969e-9b03-4f30-b4c6-b4b80ceff106 --mbrtogpt -- /dev/sdb' failed with status code 4", "stderr_lines": ["Could not create partition 2 from 10487808 to 20973567", "Error encountered; not saving changes.", "'/sbin/sgdisk --new=2:0:+5120M --change-name=2:ceph journal --partition-guid=2:e4d6155e-224b-45e6-97fd-437b1c512dd8 --typecode=2:45b0969e-9b03-4f30-b4c6-b4b80ceff106 --mbrtogpt -- /dev/sdb' failed with status code 4"], "stdout": "", "stdout_lines": []}
failed: [rhel-osd0] (item=[{'_ansible_parsed': True, 'stderr_lines': [], '_ansible_item_result': True, u'end': u'2017-09-15 14:05:51.613405', '_ansible_no_log': False, u'stdout': u'', u'cmd': u"parted --script /dev/sdb print | egrep -sq '^ 1.*ceph'", u'rc': 1, 'item': [{'_ansible_parsed': True, 'stderr_lines': [], '_ansible_item_result': True, u'end': u'2017-09-15 14:05:49.859364', '_ansible_no_log': False, u'stdout': u'', u'cmd': u"readlink -f /dev/sdb | egrep '/dev/([hsv]d[a-z]{1,2}|cciss/c[0-9]d[0-9]p|nvme[0-9]n[0-9]p)[0-9]{1,2}|fio[a-z]{1,2}[0-9]{1,2}$'", u'rc': 1, 'item': u'/dev/sdb', u'delta': u'0:00:00.007687', u'stderr': u'', u'changed': False, u'invocation': {u'module_args': {u'warn': True, u'executable': None, u'_uses_shell': True, u'_raw_params': u"readlink -f /dev/sdb | egrep '/dev/([hsv]d[a-z]{1,2}|cciss/c[0-9]d[0-9]p|nvme[0-9]n[0-9]p)[0-9]{1,2}|fio[a-z]{1,2}[0-9]{1,2}$'", u'removes': None, u'creates': None, u'chdir': None}}, 'stdout_lines': [], 'failed_when_result': False, u'start': u'2017-09-15 14:05:49.851677', 'failed': False}, u'/dev/sdb'], u'delta': u'0:00:00.019700', u'stderr': u'', u'changed': False, u'invocation': {u'module_args': {u'warn': True, u'executable': None, u'_uses_shell': True, u'_raw_params': u"parted --script /dev/sdb print | egrep -sq '^ 1.*ceph'", u'removes': None, u'creates': None, u'chdir': None}}, 'stdout_lines': [], 'failed_when_result': False, u'start': u'2017-09-15 14:05:51.593705', 'failed': False}, {'_ansible_parsed': True, 'stderr_lines': [], '_ansible_item_result': True, u'end': u'2017-09-15 14:05:49.859364', '_ansible_no_log': False, u'stdout': u'', u'cmd': u"readlink -f /dev/sdb | egrep '/dev/([hsv]d[a-z]{1,2}|cciss/c[0-9]d[0-9]p|nvme[0-9]n[0-9]p)[0-9]{1,2}|fio[a-z]{1,2}[0-9]{1,2}$'", u'rc': 1, 'item': u'/dev/sdb', u'delta': u'0:00:00.007687', u'stderr': u'', u'changed': False, u'invocation': {u'module_args': {u'warn': True, u'executable': None, u'_uses_shell': True, u'_raw_params': u"readlink -f /dev/sdb | egrep '/dev/([hsv]d[a-z]{1,2}|cciss/c[0-9]d[0-9]p|nvme[0-9]n[0-9]p)[0-9]{1,2}|fio[a-z]{1,2}[0-9]{1,2}$'", u'removes': None, u'creates': None, u'chdir': None}}, 'stdout_lines': [], 'failed_when_result': False, u'start': u'2017-09-15 14:05:49.851677', 'failed': False}, u'/dev/sdb']) => {"changed": true, "cmd": ["ceph-disk", "prepare", "--cluster", "ceph", "--filestore", "/dev/sdb"], "delta": "0:00:00.374064", "end": "2017-09-15 14:05:53.452243", "failed": true, "item": [{"_ansible_item_result": true, "_ansible_no_log": false, "_ansible_parsed": true, "changed": false, "cmd": "parted --script /dev/sdb print | egrep -sq '^ 1.*ceph'", "delta": "0:00:00.019700", "end": "2017-09-15 14:05:51.613405", "failed": false, "failed_when_result": false, "invocation": {"module_args": {"_raw_params": "parted --script /dev/sdb print | egrep -sq '^ 1.*ceph'", "_uses_shell": true, "chdir": null, "creates": null, "executable": null, "removes": null, "warn": true}}, "item": [{"_ansible_item_result": true, "_ansible_no_log": false, "_ansible_parsed": true, "changed": false, "cmd": "readlink -f /dev/sdb | egrep '/dev/([hsv]d[a-z]{1,2}|cciss/c[0-9]d[0-9]p|nvme[0-9]n[0-9]p)[0-9]{1,2}|fio[a-z]{1,2}[0-9]{1,2}$'", "delta": "0:00:00.007687", "end": "2017-09-15 14:05:49.859364", "failed": false, "failed_when_result": false, "invocation": {"module_args": {"_raw_params": "readlink -f /dev/sdb | egrep '/dev/([hsv]d[a-z]{1,2}|cciss/c[0-9]d[0-9]p|nvme[0-9]n[0-9]p)[0-9]{1,2}|fio[a-z]{1,2}[0-9]{1,2}$'", "_uses_shell": true, "chdir": null, "creates": null, "executable": null, "removes": null, "warn": true}}, "item": "/dev/sdb", "rc": 1, "start": "2017-09-15 14:05:49.851677", "stderr": "", "stderr_lines": [], "stdout": "", "stdout_lines": []}, "/dev/sdb"], "rc": 1, "start": "2017-09-15 14:05:51.593705", "stderr": "", "stderr_lines": [], "stdout": "", "stdout_lines": []}, {"_ansible_item_result": true, "_ansible_no_log": false, "_ansible_parsed": true, "changed": false, "cmd": "readlink -f /dev/sdb | egrep '/dev/([hsv]d[a-z]{1,2}|cciss/c[0-9]d[0-9]p|nvme[0-9]n[0-9]p)[0-9]{1,2}|fio[a-z]{1,2}[0-9]{1,2}$'", "delta": "0:00:00.007687", "end": "2017-09-15 14:05:49.859364", "failed": false, "failed_when_result": false, "invocation": {"module_args": {"_raw_params": "readlink -f /dev/sdb | egrep '/dev/([hsv]d[a-z]{1,2}|cciss/c[0-9]d[0-9]p|nvme[0-9]n[0-9]p)[0-9]{1,2}|fio[a-z]{1,2}[0-9]{1,2}$'", "_uses_shell": true, "chdir": null, "creates": null, "executable": null, "removes": null, "warn": true}}, "item": "/dev/sdb", "rc": 1, "start": "2017-09-15 14:05:49.851677", "stderr": "", "stderr_lines": [], "stdout": "", "stdout_lines": []}, "/dev/sdb"], "rc": 1, "start": "2017-09-15 14:05:53.078179", "stderr": "Could not create partition 2 from 10487808 to 20973567\nError encountered; not saving changes.\n'/sbin/sgdisk --new=2:0:+5120M --change-name=2:ceph journal --partition-guid=2:026ca94b-b443-41d7-87ec-ff90f29c37b8 --typecode=2:45b0969e-9b03-4f30-b4c6-b4b80ceff106 --mbrtogpt -- /dev/sdb' failed with status code 4", "stderr_lines": ["Could not create partition 2 from 10487808 to 20973567", "Error encountered; not saving changes.", "'/sbin/sgdisk --new=2:0:+5120M --change-name=2:ceph journal --partition-guid=2:026ca94b-b443-41d7-87ec-ff90f29c37b8 --typecode=2:45b0969e-9b03-4f30-b4c6-b4b80ceff106 --mbrtogpt -- /dev/sdb' failed with status code 4"], "stdout": "", "stdout_lines": []}


It seems that it isn't purging or zapping virtual disks.

The VMs were created with RHEL 7.4, with a system disk sda, and for OSD nodes a separate disk for the osd sdb.