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

"Caught in the "latest" trap again." Not sure I understand what you mean by "trap"

"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."

This is incorrect.

Back up your Mac with Time Machine

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"Time Machine automatically makes hourly backups for the past 24 hours, daily backups for the past month, and weekly backups for all previous months. The oldest backups are deleted when your backup disk is full."

I've had this backup drive since the purchase of the machine, about 4 years. I remember a few years ago when I reached the limit of space and was alerted that Time Machine would start to delete older files. This has likely occurred numerous times since that warning.

So something else has happened.

This is my last post in this thread, to insure that others who find it get an accurate picture of the situation.

"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." - Garrett Cobarr

That was the original stated condition when I started this post. I have been using Time Machine since its release in late 2007. In that roughly 7 years that has meant 3 MacBook Pros and 2 desktops and yet never encountering the aforementioned issue until now, quite a run. All with the same backup policy of a 1 to 1 size ratio on the MacBooks.

Earlier, I quoted the Apple Support docs on Time Machine's function in regards to filling a backup disk and needing to continue with a new backup – it dumps older files, it does not throw an error.

"Time Machine automatically makes hourly backups for the past 24 hours, daily backups for the past month, and weekly backups for all previous months. The oldest backups are deleted when your backup disk is full." Apple Support Docs.

To insure that I had not misunderstood the docs and to sort out the issue I visited the Apple Genius Bar and was assigned a Tier 2 support person, who confirmed the Apple Support Docs, "When Time Machine reaches a full disk during a current backup it will issue a warning and ask if you wish to see that warning in the future. It does not throw and error and then stop the backup, leaving it incomplete."

"In fact it is an answer — not an opinion — and completely germane to your question. You wrote that you were unsure as to how to proceed. I answered that question. You even quoted it." – John Galt

Part 1

This is my last post in this thread, to insure that others who find it get an accurate picture of the situation.

"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." - Garrett Cobarr

That was the original stated condition when I started this post. I have been using Time Machine since its release in late 2007. In that roughly 7 years that has meant 3 MacBook Pros and 2 desktops and yet never encountering the aforementioned issue until now, quite a run. All with the same backup policy of a 1 to 1 size ratio on the MacBooks.

Earlier, I quoted the Apple Support docs on Time Machine's function in regards to filling a backup disk and needing to continue with a new backup – it dumps older files, it does not throw an error.

"Time Machine automatically makes hourly backups for the past 24 hours, daily backups for the past month, and weekly backups for all previous months. The oldest backups are deleted when your backup disk is full." Apple Support Docs.

To insure that I had not misunderstood the docs and to sort out the issue I visited the Apple Genius Bar and was assigned a Tier 2 support person, who confirmed the Apple Support Docs, "When Time Machine reaches a full disk during a current backup it will issue a warning and ask if you wish to see that warning in the future. It does not throw and error and then stop the backup, leaving it incomplete."

"In fact it is an answer — not an opinion — and completely germane to your question. You wrote that you were unsure as to how to proceed. I answered that question. You even quoted it." – John Galt

In regards to the condition I encountered, it is an opinion and it is incorrect. The policy that you choose for backup disk size and for that matter, my policy, has nothing to do with this Time Machine failure. You did not answer the question that I posted, instead you inserted your opinion on backup policy.

As the Apple Tier 2 specialist indicated the issue is in need of a firmware upgrade that would be supplied with an updated version of my current Ventura OS or beyond.

In this entire thread you have selectively ignored the company that produces the devices, operating systems and utility software, both their written material and spoken support opinion.

This is the only way that you can continue to misrepresent the problem and its possible solution.

Day before yesterday I visited the Apple Genius Bar and was assigned a Tier 2 support guy. I went for multiple reasons, not just the Time Machine issue but also the wide spread issue with Ventura and the quick closing of the Apple Store window when launched.

I posed the question about basic size needs: disk to backup and backup disk. He confirmed what I already knew that to sufficiently cover my working files and documents, a 1 gig drive is covered by a 1 gig drive. This setup will not cause the original question...

"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."

That issue is being caused by the need for a firmware upgrade, which is included in one of the two Ventura upgrades that I cannot currently access due to my Apple Store. So I am now going leap past Sonoma to Sequoia and hope for the best.

Bear in mind, I do not back up the entire drive, just the working documents, which at this writing is about 800gigs, the rest of the drive is OS, apps, etc.

Regardless, no matter how big your backdrop drive is, at some point, older files will need to be dumped. Here's where personal working habits and technical setup comes into play – and choice.

My MacBook Pro is a mobile workspace, I share all working files via SyncThing to my rack mounted Mac Pro that has a drive in the region or 10 terabytes, all of that is then backed up to a 20 terabytes remote backup system, this is accomplished with SuperDuper.

Even that capacious amount of storage, will, at some point, dump older files. That is the nature of transitory backup, unless you can afford 'infinite size backup' which does not exist, you need to make some choices. Files that need to be archived longer than years and years, like business files, I offload to optical disks.

I can understand that if your only computer is the one you need to back up, then yes, double -maybe triple the size of the backup drive. That is not my condition, my MacBook Pro with Time Machine, can cover me for the last hour if I make a dumb mistake or for that mater, going back a year or more. If my MacBook Pro gets stolen or is taken out by a meteor that I survive, then, as I am triple redundant backed up, no worries except that I have to replace a fairly expensive device.

Do not confuse what you prefer or your unique conditions with what is technically required.

"I trust my practical experience more than what I read in Apple documentation which may brush-stroke over fine details. I don't read what I want to believe, but what I observe in practical usage". – VikingOSX.

You cited no technical sources, I cited the company that makes the hardware and software and has been saying the same thing for as long as Time Machine has been available.

"If you want a more in-depth technical explanation you can search this site for the boring details, but it won't change the answer: You need more capacity. 2 TB might be sufficient." – John Galt.

Perhaps those boring details are worth your investigation in order to answer technical questions beyond urban legend and personal bias.

Again, to reiterate, the issue I have with Time Machine throwing an error and refusing to complete backup is a firmware update need, it is not an issue with the size of my backup drive.

Thanks for the tip. I use something very similar, SanDisk Extreme PRO Portable SSD.

With each iteration of a new computer and more internal storage I buy an ever larger external. The Sandisk is rugged, dust and water proof, although I have not put it to that full test. It has a much smaller and simpler connector that the one you picture, Thunderbolt on both ends.

And yes, it goes wherever the MacBook Pro goes.

Your opinion is worthy but, sadly, it has nothing to do with the issue posted.

"I have no such need. I've done it already. If you want to investigate, that's your job." – John Galt

Then the question is, why did you reply? Is this how you rack up points?