I did research this topic and the most recent answer to this question is from 2018. There have been many firmware updates and changes and thought it is worth asking again. I have the 5D, 5N & 5N2. Currently, Time Machine is on the 5D because it is DAS Thunderbolt, I would consider switching it to a different unit if it would be better served.
First, how is it possible that the drive is even full? I don’t think Time Machine is deleting old backups. I checked my settings, all is good there. My total drive space is 6TB, so I made the capacity 20TB, with a little cushion.
Second, I can swap out the red drive and increase total capacity, that is the easy part, but that will not solve the volume size issue. Is it possible to increase Volume Max Capacity without losing the content of the volume?
Thank you for your time.