Comment 4 for bug 1581221

This can also happen when the device starts out unused, but is listed multiple times in the block-device config option. For example:

    value: /dev/disk/by-id/wwn-0x50014ee25eda851b /dev/disk/by-id/wwn-0x50014ee2b4301798
      /dev/disk/by-id/wwn-0x50014ee2b4302108 /dev/disk/by-id/wwn-0x50014ee2b43021d3
      /dev/disk/by-id/wwn-0x50014ee2b43162b6 /dev/nvme0n1 /dev/nvme0n1 /dev/nvme0n1

Leads to:
2016-05-15 03:22:32 INFO config-changed Physical volume "/dev/nvme0n1" successfully created
2016-05-15 03:22:32 INFO juju-log [cinder] pvscan: PV /dev/nvme0n1 lvm2 [372.61 GiB]
  PV /dev/sdb lvm2 [931.51 GiB]
  Total: 2 [1.27 TiB] / in use: 0 [0 ] / in no VG: 2 [1.27 TiB]

2016-05-15 03:22:32 INFO config-changed Volume group "cinder-volumes" not found
2016-05-15 03:22:32 INFO config-changed Volume group "cinder-volumes" successfully created
2016-05-15 03:22:33 INFO config-changed Volume group "cinder-volumes" successfully extended
2016-05-15 03:22:33 INFO config-changed Physical volume '/dev/nvme0n1' is already in volume group 'cinder-volumes'
2016-05-15 03:22:33 INFO config-changed Unable to add physical volume '/dev/nvme0n1' to volume group 'cinder-volum
es'.
2016-05-15 03:22:33 INFO config-changed Traceback (most recent call last):
...

See more of the juju log here: http://paste.ubuntu.com/16451905/

Full logs are attached.