Why does the free space remain constant for so many hours then begin to decrease?
The free space reflects the size of the disk minus the size of the FSY file. Thus a decrease in the free space means that the FSY file has increased in size. The size of the FSY file will increase from the moment when the TelliCast software is first started. However, once the size of data segments has stabilised (one complete set of data has been received), the size of the FSY file will tend to be constant. It may well be that some new data comes along – a CRM file or your first Metop segment – which needs more total space, and hence the FSY file will once again increase in size. It’s also possible that in poor reception conditions, incomplete data will be left in the FSY file, once again causing an increase. This incomplete data is automatically removed after a certain time, but the software never decreases the size of the FSY file, so the free space will never increase.