Too many huge Time Machine Backup.backupdb files

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Level 1

8 points

Too many huge Time Machine Backup.backupdb files

Hi, I use a Samsung T5 500GB external SSD for Time Machine via USB connection. Sturdy.

Time Machine now says it is 470GB full and effectively unusable, but the source MacBook hard disk (250GB) contains only 193GB ALL UP. (btw: Catalina 10.15.7)

How does TM fill up a 500GB drive with that?

When I looked into the ext.SSD's 'Backups.backupdb' I find 5 instances of very large Backups... 123GB...121GB...118GB ... 125GB ...117GB ...all between May and July 2022. Surely this is not incremental?? (...and how did all those back then fit in a 500GB drive?)

Trying to research what to do, and everybody says Time Machine automatically deletes older backups according to its own wisdom, and that I should not tamper.... That I should just buy a new drive and carry on, as there is nothing good I can do ...Grrr... is this right?

Thank you for considering.

MacBook Pro 13″

Posted on Apr 24, 2023 12:28 AM

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Answer 1

Top-ranking reply

John Galt

Level 10

145,720 points

Apr 24, 2023 10:39 AM in response to eliotmess

Does Time Machine indicate an inability to create a backup? What is its exact wording?

(...and how did all those back then fit in a 500GB drive?)

Your observations are correct, but the calculation you imply is meaningless due to the way APFS calculates disk space.

The bottom line is that if Time Machine says it needs more space, then it needs more space. Is that in fact the case?

For reference: If the Time Machine backup disk for your Mac is full - Apple Support

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Answer 2

eliotmess Author

Level 1

8 points

Apr 26, 2023 9:28 PM in response to John Galt

The SuperDuper Copy is a state copy run monthly. It is not granular.

My Data Security plan is:

Catastrophic failure / Ransomware -> Erase and reinstall from SuperDuper or buy new machine and do same
Glitch that loses work (long consultancy reports) since last SuperDuper backup -> restore data from Time Machine....
Document I'm working on tonight...keep resaving advancing work hourly, with incremental naming. Ensure Microsoft Autosave is OFF.
Cannot find something historical that 'should be there': Check Time Machine and Email Archives.

So SuperDuper is not granular is why.

Why are we're not getting any clearer as to why many of the backups are over 115GB? Time Machine supposed to be incremental backup, e.g. a few gigabytes each time. And that was how it was from Aug 2021 to May 2022.

I'm not accepting ObviousCaptain's opinion is that the whole content gets backed up every time.

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Answer 3

John Galt

Level 10

145,720 points

Apr 25, 2023 4:25 AM in response to eliotmess

There are some steps you can take to possibly determine the reason, but they will probably just satisfy my own selfish curiosity than help you fix what's wrong, and I agree something appears to be wrong.

I assume you have no need for backups that old. If that's the case one solution is to simply erase the backup drive and start a new set. Of course you should not need to do that, since TM should be erasing old and "expired" backups on its own.

Since you already examined the backup disk's contents, can you post a screenshot of that Finder window? Remember to "look but don't touch" because manually altering a backup disk using the Finder (in other words, dragging an item to the Trash) will absolutely, positively corrupt its contents making the backup useless.

I'm interested in seeing something like this:

That is a backup disk just recently placed into service. A backup disk that has been in service for nearly a year will have perhaps fifty of those entries. Yours, dating back to 2021, probably has a hundred. Are there any other top-level entries?

... this ext SSD's TM backups go back to mid-2021.

What information are you using to make that determination? The TM menu icon's reported date range, or did you actually "enter time machine" to verify you can navigate back that far and actually restore a backed up item. Which one may point to a different potential solution.

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Answer 4

eliotmess Author

Level 1

8 points

Apr 26, 2023 2:30 AM in response to John Galt

So these are the oldest ones in the ExtSSD.

It's only after 3 May 2022 that the enormous backups start.

I can tell you that I installed MacOS Catalina 26 Feb 2022, and then I had to Update SuperDuper to an APFS version on 21 March 2022.

Its still calculating sizes, but here are the next 2 months:

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Answer 5

Apr 26, 2023 5:08 AM in response to John Galt

Do you really need all those backups? Uncheck "Backup Automatically" and do it manually when you have more content to back up. Then delete the old ones.

System Prefs > Time machine > adjust auto backup setting

The backup size should be almost exactly as large as the HD you're backing up.

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