We have 20 or so backups on a 3TB drive. We need to go into each backup and delete some specific folders from each.

Attempting to do so via Finder brings up "backup items cannot be modified". We tried to modify the permissions which took a long time but this didn't help.

macOS Catalina 10.15.7

  • Is the backup on a APFS or HFS volume?
    – mmmmmm
    Sep 14, 2021 at 14:35
  • 2
    HFS+ for Catalina. APFS only for Big Sur onwards.
    – Tetsujin
    Sep 14, 2021 at 14:40

1 Answer 1


Golden rule: Never try to delete Time Machine from Finder.
If you're lucky it won't let you. If you're unlucky it will - & that's no end of trouble.

To delete the entire history of a file or folder, first select it in Finder then from the Time Machine menu bar item, select Enter Time Machine

You can then right click your unwanted item & select "Delete all Backups of…"

enter image description here

If the history goes back a long way, this may take quite some time. Be patient.

  • Perfect. Many thanks. We don't intend to use in TimeMachine again, only to send the drive to a client, although we've opted to instead encrypt the drive first, then copy over the files we need. Sep 14, 2021 at 15:01
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    @Tetsujin FWIW, this advice is rock solid for non-APFS Time Machine volumes. But for APFS volumes this doesn’t work at all anymore. I also just posted another question that is slightly similar to this one, but about removing a stray backup of a whole volume from an APFS Time Machine backup. Yes, I am using this comment to point out one thing but also (hopefully) getting some sage advice from Tetsujin. Nov 26, 2021 at 18:24
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    @Giacomo1968 - thank you for the vote of confidence ;) but I don't really have a great deal of knowledge on the new APFS Time Machine structure. I see you're picking up some good info on your linked question, though. Wish you luck:)
    – Tetsujin
    Nov 27, 2021 at 11:20
  • 1
    You can read more about the specifics of being unable to delete files from APFS backups here: eclecticlight.co/2022/07/19/… Jan 20 at 0:08
  • 1
    With encrypted drives, you can only delete backups with tmutils To do so, find backups: $ tmutil listbackups Delete desired backup: $ sudo tmutil delete -p BACKUPPATH With BACKUPPATH = /Volumes/...
    – vintagexav
    Feb 20 at 16:02

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