Description of problem:

This bug is opened on the basis of an ongoing discussion on https://bugzilla.redhat.com/show_bug.cgi?id=1911669#c6 & probable issue with ceph-volume.

So basically during filestore to bluestone migration  during FFU(13 to 16.1) following tasks fail with 

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4. During filestore to bluestore migration it does moved ahead as compared to last time but failed at  

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/var/lib/mistral/425e8b9d-5f37-4c57-8457-9e276fe8a540/ceph-ansible/ceph_ansible_command.log

2021-01-19 09:05:19,311 p=792867 u=root n=ansible | fatal: [overcloud-computehci-0]: FAILED! => {"changed": true, "cmd": ["podman", "run", "--rm", "--privileged", "--net=host", "--ipc=host", "--ulimit", "nofile=1024:4096", "-v", "/run/lock/lvm:/run/lock/lvm:z", "-v", "/var/run/udev/:/var/run/udev/:z", "-v", "/dev:/dev", "-v", "/etc/ceph:/etc/ceph:z", "-v", "/run/lvm/:/run/lvm/", "-v", "/var/lib/ceph/:/var/lib/ceph/:z", "-v", "/var/log/ceph/:/var/log/ceph/:z", "--entrypoint=ceph-volume", "undercloud.ctlplane.localdomain:8787/rhceph/rhceph-4-rhel8:latest", "--cluster", "ceph", "lvm", "batch", "--filestore", "--yes", "--prepare", "--journal-size", "512", "/dev/vdb", "/dev/vdc"], "delta": "0:00:02.627383", "end": "2021-01-19 14:05:19.270717", "msg": "non-zero return code", "rc": 1, "start": "2021-01-19 14:05:16.643334", "stderr": "Running command: /usr/sbin/vgcreate --force --yes ceph-filestore-5cb2df37-7c07-4fc4-a4e1-a03d85a3dd52 /dev/vdb\n stdout: Wiping dos signature on /dev/vdb.\n stdout: Physical volume \"/dev/vdb\" successfully created.\n stdout: Volume group \"ceph-filestore-5cb2df37-7c07-4fc4-a4e1-a03d85a3dd52\" successfully created\nRunning command: /usr/sbin/vgcreate --force --yes ceph-filestore-47b4d6d1-6dde-4967-96da-aabd83890e20 /dev/vdc\n stdout: Wiping dos signature on /dev/vdc.\n stdout: Physical volume \"/dev/vdc\" successfully created.\n stdout: Volume group \"ceph-filestore-47b4d6d1-6dde-4967-96da-aabd83890e20\" successfully created\n-->  TypeError: unsupported operand type(s) for /: 'int' and 'NoneType'", "stderr_lines": ["Running command: /usr/sbin/vgcreate --force --yes ceph-filestore-5cb2df37-7c07-4fc4-a4e1-a03d85a3dd52 /dev/vdb", " stdout: Wiping dos signature on /dev/vdb.", " stdout: Physical volume \"/dev/vdb\" successfully created.", " stdout: Volume group \"ceph-filestore-5cb2df37-7c07-4fc4-a4e1-a03d85a3dd52\" successfully created", "Running command: /usr/sbin/vgcreate --force --yes ceph-filestore-47b4d6d1-6dde-4967-96da-aabd83890e20 /dev/vdc", " stdout: Wiping dos signature on /dev/vdc.", " stdout: Physical volume \"/dev/vdc\" successfully created.", " stdout: Volume group \"ceph-filestore-47b4d6d1-6dde-4967-96da-aabd83890e20\" successfully created", "-->  TypeError: unsupported operand type(s) for /: 'int' and 'NoneType'"], "stdout": "", "stdout_lines": []}

5. Manual run of command does create vg but exits with TypeError.

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[root@overcloud-computehci-0 ~]# podman run --rm    --privileged    --net=host    --ipc=host    --ulimit    nofile=1024:4096    -v    /run/lock/lvm:/run/lock/lvm:z    -v    /var/run/udev/:/var/run/udev/:z    -v    /dev:/dev    -v    /etc/ceph:/etc/ceph:z    -v    /run/lvm/:/run/lvm/    -v    /var/lib/ceph/:/var/lib/ceph/:z    -v    /var/log/ceph/:/var/log/ceph/:z    --entrypoint=ceph-volume    undercloud.ctlplane.localdomain:8787/rhceph/rhceph-4-rhel8:latest    --cluster    ceph    lvm    batch    --filestore    --yes    --prepare    --journal-size    512    /dev/vdc 
Running command: /usr/sbin/vgcreate --force --yes ceph-filestore-372dc517-9bc5-4b1b-8ac2-3a56e589bde7 /dev/vdc
 stdout: Volume group "ceph-filestore-372dc517-9bc5-4b1b-8ac2-3a56e589bde7" successfully created
-->  TypeError: unsupported operand type(s) for /: 'int' and 'NoneType'
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Version-Release number of selected component (if applicable):
RHCS-4

How reproducible:
100%

Steps to Reproduce:
1.
2.
3.

Actual results:
It fails

Expected results:
it should pass 

Additional info: