With your help, I finally found the problem.

I added a blacklist.conf file in /etc/carbon/ and by default the graphs starting with this are deleted:

\.\.
^\.
\.$

I've put in a comment #\.\. and everything works fine.

I am sorry for the inconvenience.
Many thanks for the development of NAV

Regards,
Nicolas

On Mon, 14 Sep 2020 13:29:27 +0200 Biselx Nicolas <nicolas.biselx@epfl.ch> wrote:

Hi,

here's the debug trace

[snip]

{
    OID(".2"): {
        "pethMainPsePower": 1825,
        "pethMainPseOperStatus": 1,
        "pethMainPseConsumptionPower": 147,
        0: OID(".2"),
    },
    OID(".5"): {
        "pethMainPsePower": 1825,
        "pethMainPseOperStatus": 1,
        "pethMainPseConsumptionPower": 53,
        0: OID(".5"),
    },
    OID(".6"): {
        "pethMainPsePower": 1825,
        "pethMainPseOperStatus": 1,
        "pethMainPseConsumptionPower": 40,
        0: OID(".6"),
    },
    OID(".7"): {
        "pethMainPsePower": 1825,
        "pethMainPseOperStatus": 1,
        "pethMainPseConsumptionPower": 51,
        0: OID(".7"),
    },
}

ipdevpoll does apparently pull real power data for 4 separate PoE groups
here, so the problem must either be with getting the data stored in
Graphite, or retrieved from Graphite.

I would attempt to use Graphite directly to render the contents of the
expression `nav.devices.ca-bi-02_epfl_ch.system.power.*`, to confirm
there is real power data stored there.

Furthermore, I would use the network tab of the browser's web developer
tools to confirm that the NAV web ui is actually fetching the render
data from said Graphite path, and getting a proper response with data in
it.