def check_ceph_df():

    try:
        res = subprocess.check_output(["ceph", "df", "--format=json"],
                                      stderr=subprocess.STDOUT)
        exit_code, message = interpret_output_df(res)
        sys.stdout.write("%s\n" % message)
        sys.exit(exit_code)
    except subprocess.CalledProcessError as e:
        sys.stdout.write('CEPH UNKNOWN: %s\n' % e.output)
        sys.exit(3)
    except OSError:
        sys.stdout.write('CEPH UNKNOWN: unable to launch ceph health\n')
        sys.exit(3)
Slip should always be > 0 and < 1.
dataset/ETHPy150Open openstack/monitoring-for-openstack/oschecks/ceph.py/check_ceph_df--crossover with--dataset/ETHPy150Open heiskr/sagefy/server/test/test_modules_sequencer_guess_and_slip.py/test_slip_range