please create upload logfile on SD-Card
currently there is no logfile created on the SD-Card which contains the upload status of the last (or all) upload attempts.
At least I did not find any in the part which is visible in the Show SD Card Contents directories of OBS-Unit.
At the end of an upload process initiated by pressing the hardware button you just get the information which is shown on the bottom of the screen

There are various reasons why the upload may fail:
- no or wrong Upload Url
- no or wrong API key
- no connection to the upload host
- breaking connection during upload
- file was already uploaded to the OBS-server
In order to ease finding the root cause for failed uploads it would be very helpfull to have a logfile with detailed error messages.
If you do the upload using the web ui, you can see the message, if you hover over the error indicating red cross, as a tool-tip.
Related to #96
Also: If this feature is implemented it makes sense to also have the time of the failed uploads in the logs - Allowing to potentially cross-check with server side logs.
Could you already detect the cause by using the web ui for the upload?
I prefer a more user friendly and resolvable way. To access the log on the SD Card you also have to start the OBS in server mode and connect to it. So making the error display in case of a upload error via the web ui more verbose could be sufficient here?