So I hadn’t opened up my MacBook in awhile, and, when I finally did, was constantly greeted with There isn’t enough space 😣
A bit frustrating at first since I thought the whole Time Machine allure was that old backups would automatically be deleted 🤔
So after a few weeks of getting this annoying message each night finally decided to think this through.
Realized that, yes, I had configured Time Machine to back up to my Synology NAS automatically so I didn’t have to think about it, so I decided to check the DSM for clues as to what was going on.
So I opened up File Station, right clicked Time Machine Backups and right clicked Properties to find that yes, the volume was nearly full.
Then I opened up Control Panel > Shared Folder then right clicked Time Machine Backups to select Edit where I found Empty Recycle Bin.
Emptying the recycle bin resolved all the issues which then reminded me that Time Machine on my MacBook had indeed been properly deleting old backups but that the NAS as configured will only free up space once the recycle bins are emptied. I configured this on purpose months ago to ensure that if a machine on the local network ever got compromised that a virus or other malicious activity could not remotely delete backups once they were completed. I suppose I could enable auto emptying of recycle bins or disable them altogether for Time Machine Backups since a backup of that volume is done nightly to a volume that is inaccessible to the network 🤔