I have come across a problem data logging a SMD120 meter, The emonpi has been data logging for more then 2 years without fault from a set of SMD120 meters, but just as late it has stopped working, when checking things, the emonhub log shows the data from the SMD120 is being read as I see all its values in the emonhub log, but when looking at the inputs and feeds there are many missed feeds some as many as hours without showing in the input or feeds tab, Just any ideas on what is happening, or could it be a failing memory card?
Have you been doing updates in that time?
Have a look on the Admin page and check Memory usage.
The next culprit could be a full log folder, but you can only check that by SSH in to the Pi (then df -h). Plenty of threads on full log folder.
@TrystanLea - this would be a good thing to add to the Admin Page.
It might be, but 2 years is not that long.