Obviously there is more than enough space to execute the recording. Permissions appear correct as well. Possibly related to random PMS inaccessible on local network errors. Dumps have been uploaded to Plex. Relevant logfile attached. Plex Media Server.1.log (3.9 MB)
root@plex:/Media/TV Shows# ls -la
total 32
drwxrwxr-x 68 plex plex 4096 Jan 22 21:13 .
drwxrwxr-x 5 plex plex 65 Jan 2 08:54 ..
drwxr-xr-x 3 plex plex 62 Jan 27 20:31 .grab
Jan 27, 2019 20:30:07.197 [0x7f2d6f7fe700] DEBUG - DVR:Subscription: There are 67 active grabs at the end.
Jan 27, 2019 20:30:07.197 [0x7f2d917fa700] WARN - Low disk space: 16EB source file, 5.46TB capacity, 1.86TB available on "/Media/TV Shows/.grab"
Jan 27, 2019 20:30:07.197 [0x7f2d917fa700] ERROR - DVR:Grabber: Not enough free space in "/Media/TV Shows/.grab"
Jan 27, 2019 20:30:07.197 [0x7f2d917fa700] DEBUG - DVR:Grabber: Operation for 'Big Brother: Celebrity Edition - E5 - Episode 5' on channel 2.1 completed with status error (There was not enough free disk space to start the recording)
Jan 27, 2019 20:30:07.197 [0x7f2d917fa700] DEBUG - Activity: Ended activity dfc78612-1340-493b-b41e-1623142995fa.