Can deleting time machine backup files affect system files

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Can deleting time machine backup files affect system files

I have a 2 TB external hard drive that I have used for both file storage and time machine backups for my last three computers (mac Air, mac pro 2018 and my current mac pro 2024).

I reached the limit of the EHD storage space trying to do a time machine backup of my current macbook pro. Since most of the storage is taken up by backups of my older devices, time machine wasn't going to overwrite these automatically, so I decided to move the time machine files from the backups.backupsdb folders for those devices to the trash to clear up storage space on the EHD.

Trying to empty the trash was taking hours, so I gave up on this and I think I'll just reformat/wipe the drive and start backing up the computer straight away.

My problem is that when emptying the trash, I got a warning saying that some of the files I was trying to delete were in use. Is there any chance that I've accidentally deleted files from my current macbook pro's SSD that have similar names/directories in the EHD, or are these always completely separate?

Thanks for your help

Posted on Jun 2, 2025 4:15 AM

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Answer 1

Top-ranking reply

Grant Bennet-Alder

Level 10

143,359 points

Jun 2, 2025 12:59 PM in response to Dragonfruit2025help

the appropriate advice for deleting Time Machine files is: DON'T

They are triple-locked, and can not be removed by ordinary means. If you manage to wrestle some of them into the Trash, they will remain there permanently.

that error message is an indication that those files are locked, nothing more.

your ONLY recourse to get rid of them (unless you can choose 'Put-Away) is to erase the drive.

NB> Time Machine no longer allows any other files to be casually stored on its drive. This will be enforced after you assign the 'new' drive to Time Machine.

another note: Time Machine has always supported MULTIPLE drives for backup destinations. Each drive is a stand-alone backup set, and every-other backup goes to every-other drive.

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Answer 2

MrHoffman

Level 10

152,405 points

Jun 2, 2025 1:03 PM in response to Dragonfruit2025help

Erase the external hard disk drive to clear the current contents.

Or consider a larger replacement hard disk drive, as this one is approaching a decade, and is already clearly also storage-constrained.

Current HDD sizes are as much as 32 terabytes, and 40 terabytes and larger HDDs are available.

I tend to use 4 to 5 TB HDDs for Macs with a terabyte or maybe two of internal storage, as that provides both depth of backups, and avoids the “fun” Time Machine can encounter with large file churn on smaller HDDs. Or use NAS, which avoids having to cable the HDD to a MacBook Pro or MacBook Air.

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Can deleting time machine backup files affect system files

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