'Returns the provisioned capacity.
Get the sum of sizes of volumes, snapshots and any other
files on the mountpoint.'

def _get_provisioned_capacity(self):

    provisioned_size = 0.0
    for share in self.shares.keys():
        mount_path = self._get_mount_point_for_share(share)
        (out, _) = self._execute('du', '--bytes', mount_path, run_as_root=self._execute_as_root)
        provisioned_size += int(out.split()[0])
    return round((provisioned_size / units.Gi), 2)
