I store all my movies, TV programs and music on an external 10TB hard drive. I use Norton back-up to safeguard loss by backing up to another 10TB external drive. I have 2.3TB of unused space but still get errors after back-up for a number of movies and programs indicating "Not enough space". The files in question are no different to all the others, .mp4.
Hello Scully. Is the backup trying to backup ALL the files previously backed up in addition to new files? If so that is the issue. The optimal would be incremental backup so that ONLY changed and new files are backed up. I recommend using Macrium Reflect since it is straight forward and easy to use.
https://www.macrium.com/
https://blog.macrium.com/incremental-vs-differential-backup-what-are-the-differences-and-how-do-they-compare-3213b093b56a?external_link=true.
SA