Time Machine Error Refuses to Write Over Old Backups

[Tenarrows]

I've had a 2TB external HD as my back up drive for two years. Time Machine suddenly says the following:

"The backup disk ran out of space unexpectedly. Time Machine will try to make more space available by removing expired backups during the next scheduled backup."

I tried another backup manually and I received the same message. I click ok allowing it to overwrite old backups and it runs for 5 minutes and stops again with the same error message.

My Time Machine is set to delete oldest backups and it was never an issue before.

 

[Kaveman]

Eject the drive.
Turn the drive off.
Unplug the drive from Power and Mac and leave it off for 5+ minutes.
Restart the Mac
Power up the drive and replug into the Mac
try again.

 

[Tenarrows]

Kaveman, thanks for the suggestion. I followed your instructions and unfortunately the problem persists.

TM says for example: 18.5 GB available. Backing up 1.27 GB of 14.19 GB. I don't know if this is normal but as the backup continues the "of" part (14.19) becomes a bigger number. Again when I open TM prefs it says, "The oldest backups are deleted when your disc becomes full." But it gives me an error message instead.

I also tried to delete older backups manually in order to create more free space and that didn't help either.

 

[Spawn_Dooley]

What OS X version are you on? Have you recently upgraded your OS? Are there any non-TM files stored on the same partition?

In System Preferences ~> Time Machine ~> Options, what does it say as the "Estimated size of full backup"?

Is the Time Machine drive listed in the "Exclude these items from backups" list?

 

[Tenarrows]

Thanks for helping Spawn. I was able to resolve the issue last night. I did several things:

(1) Trashed the TM plist file and restarted the computer.
(2) Ran verify and repair permissions on the external and internal drive.
(3) Trashed the last incomplete TM backup folder.

I realized after multiple error messages it appeared TM wanted to complete the last unfinished backup which is where it was hitting a wall. So on a hunch I thought maybe the last backup was corrupted. I think out of the three steps I took that was the answer.

TM is working as it should again.