Home Forums Mac Software Mac Operating Systems Time Machine not dropping oldest files

My Time Machine is set up to drop the oldest files, to make room for new backups. That's more than okay for me as it makes the oldest files about three years old. My main drive is also 1TB with only 324 GB used. However Time Machine ( (1TB drive) now says:

"Time Machine couldn’t complete the backup to Time Machine. An error occurred while copying files. The problem may be temporary. If the problem persists, use Disk Utility to repair your backup disk. Latest successful backup: Yesterday, 1:34 PM"

So, I had Disk Utility run a repair, which took a very long time, but it seemed to do a lot of stuff. However, the above message has re-appeared.

Time Machine only drops the oldest files when your backup drive runs out of room to store new backups and IIRC spcifically notifies you when that is about to happen. You description appears to imply that is not the issue. However, Disk Utility > First Aid does not always complete volume repairs on the first pass. Try runnning First Aid a second, even third, time.

Yes. It's a checkbox you select if you want the notifications.

Will do.

I hope that works but, If multiple runs of First Aid are unsuccessful in returning your Time Machine Drive to service, run DriveDX (they have a free trial offer), Drive Scope, TechTool Pro, or any other utility that checks and reports the full panoply of S.M.A.R.T. (and NVME) data to be sure the physical drive itself is still mechanically healthy.

Did do.....three times. Shutdown after first run; restart after second run; regular log out after third run. So far the Dialogue Box hasn't shown up again, however, neither has Time machine done any more backups. The last one is still April 1st. Oh wait, could this be? Na....Apple wouldn't do that.

Will do.

Is Back Up Automatically still checked in Time Machine prefs?

Good catch. No it wasn't....but is now.

Have done and DriveDX says the drive is 100% across the board. However, the "Time Machine couldn't complete the backup...." dialogue box has reappeared.

Well hecky-darn (or epithets t that effect). I just did a DuckDuckGo search on Time Machine couldn’t complete the backup to Time Machine. and got pages of hits, many from Apple's own discussion forums as well as Apple's official response. I leave it to you to do you own search, read, and analyze the hits as you have the complete picture.

For What It Is Worth, over the years I have had two problems with Time Machine backups failing to write and zero problems recovering individual files, versions of files, or entire systems. Both write problems were resolved following this Apple instruction...
That is why I have two Time Machine drives today.

Well, after going through all Apple's recommendations and still no resolution, I am faced with a full erase (i.e. lose three years of data) and enduring the hugely time-consuming task of starting over. In my opinion it suggests that Time Machine is just not worth the trouble.