I had issues in the past with recordings failing because of the large amount of space required to record movies, so I bought larger storage on my DVR machine - 128GB in the transcode & destination drive (the .ts files are processed and moved later).
Tonight two SD (576p) recordings failed. I checked the logs - Plex was looking for >100GB space to record each movie.
Oct 29, 2019 20:50:02.357 [0x5db10450] WARN - Low disk space: 105.33GB source file, 116.88GB capacity, 101.45GB available on “/data/Movies/.grab”
Oct 29, 2019 20:50:02.357 [0x5edff450] WARN - Low disk space: 105.33GB source file, 116.88GB capacity, 101.45GB available on “/data/Movies/.grab”
Oct 29, 2019 20:50:02.357 [0x5db10450] ERROR - DVR:Grabber: Not enough free space on volume containing “/data/Movies/.grab” and transcode cache directory
Oct 29, 2019 20:50:02.357 [0x5edff450] ERROR - DVR:Grabber: Not enough free space on volume containing “/data/Movies/.grab” and transcode cache directory
Oct 29, 2019 20:50:02.358 [0x5db10450] DEBUG - DVR:Grabber: Operation for ‘Transformers: Age of Extinction (2014)’ on channel 014 completed with status error (There was not enough free disk space to start the recording)
Oct 29, 2019 20:50:02.358 [0x5edff450] DEBUG - DVR:Grabber: Operation for ‘Cowboys & Aliens (2011)’ on channel 028 completed with status error (There was not enough free disk space to start the recording)
One recording was for 2 hours 20 mins, the other recording was for 3 hours 15 mins. This has to be a bug, surely? The finished .ts files are under 10 GB in the end.