In the dashboard of my OpenStack Ocata cloud I see that the reported memory usage is wrong for the hypervisors.

As far as I understand that information should correspond to the "used_now" field of the  "nova host-describe" command. And indeed considering an hypervisor: 

# nova host-describe cld-blu-01.cloud.pd.infn.it

+-----------------------------+----------------------------------+-----+-----------+---------+

| HOST                        | PROJECT                          | cpu | memory_mb | disk_gb |

+-----------------------------+----------------------------------+-----+-----------+---------+

| cld-blu-01.cloud.pd.infn.it | (total)                          | 8   | 32722     | 241     |

| cld-blu-01.cloud.pd.infn.it | (used_now)                       | 19  | 16259     | 23      |

| cld-blu-01.cloud.pd.infn.it | (used_max)                       | 19  | 38912     | 95      |

| cld-blu-01.cloud.pd.infn.it | b08eede75d5e4be4b0fe21e68fa9c688 | 1   | 2048      | 20      |

| cld-blu-01.cloud.pd.infn.it | 7890b3e262264529a19f9743cf2f14bc | 16  | 32768     | 50      |

| cld-blu-01.cloud.pd.infn.it | 4d8187cffa6a4085ad4a357b8a5afc03 | 2   | 4096      | 25      |

+-----------------------------+----------------------------------+-----+-----------+---------+

So for the memory it reports 16259 for used_now, while as far as far I understand it should be 38912 + the memory used by the hypervisor

Am I missing something ?

Thanks, Massimo