Time Machine has suddenly decided not to backup, not sure how to proceed

I am using the latest version of Ventura, Version 13.6.9 (22G830)

My MacBook Pro's total storage is 1 Terabyte, currently there is 173.51 GB available.

I run my Time Machine backups to an external Flash drive with a total capacity of 1 terabyte. In other words, they are equal in total size.

Today, for some reason I received the following alert:

"Time Machine couldn’t complete the backup to “PORTA XX BackUp”

Time Machine was only able to complete 81% of the backup because there is insufficient free space on the backup disk."

“PORTA XX BackUp” is the Flash drive (backup) – the MacBook Pro's drive is named "PORTA XX."

Now I understand that numerous, repeated backups are larger than backup space available, but also understood that Time Machine is supposed to automatically dump the oldest backups to make room for the newer backups.

This automatic process has now stopped. I have no idea why and I am not quite sure how fix this issue. My draconian solution is to reformat (erase) the backup drive and start a new backup from scratch.

Obviously I would like to avoid that heavy lift and find better option and even if that is the solution, I'd like to know why this took place.

Thanks.

MacBook Pro 16″, macOS 13.6

Posted on Oct 31, 2024 7:22 PM

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VikingOSX

Community+ 2024

Level 10

116,765 points

Posted on Nov 1, 2024 7:11 AM

Caught in the "latest" trap again. The current version of Ventura is 13.7.1, not 13.6.9.

Time Machine does feature the ability to remove certain older backups but that is not intended to magically make room for the size of your current backup.

The normal Time Machine drive size scaling is 2.5 - 3x the size of your internal boot drive. Your 1:1 scaling has caught up to you and to proceed, you will need more storage. That will either be in the form of a newly APFS formatted 2 TB TM SSD drive and a first backup to it or sacrificing the existing drive by reformatting it APFS and a first backup to it. I recommend the new drive approach as you lose no backup content from the now set aside 1 TB drive.

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17 replies

Old Toad

Level 10

210,603 points

Nov 7, 2024 10:17 AM in response to Garrett Cobarr

You may have to upgrade to a 2 TB drive or erase the drive and start over until you run out of room again.

Nov 7, 2024 11:31 AM in response to Tesserax

Thank you! This appears to be highly useful.

I've had other, smaller issue with Time Machine in the past.

Thanks again.

Time Machine has suddenly decided not to backup, not sure how to proceed