In the FxM(Foglight Experience Monitor) HTTP UI under Configure -> Database all the Size and Usage values show Zero (0)
This is caused by one or more of the appliances not having NTP configured and the times between the Portal and Probes are out of sync.
Configure the NTP servers on all the portal/probe appliances and verify that they are set to the same time.
NTP Servers can be configured by:
1) go to the FxM HTTP UI on each machine
2) Select Configure -> Appliance -> Network Settings
3) Fill in the NTP server IP addresses
The OS time can be set by:
1) SSH in to each FxM machine
2) Select 2 System Time configuration
3) Select 3 Change Time and follow the screens
4) Select 4 Change Timezone and verify that you have the correct timezone configured.