Somehow I lost permission to access folders in my time machine back up. Last time I copied some files from this archive was four days ago and I didn't have any problems. Today I started to make I a new time machine back up of my new MacBook Air on the same external hard drive. There wasn't enough space so I decided to delete old files. Then I realised that I lost access.

Can you please help me with this case

Thank you in advance

  • Please clarify your specific problem or provide additional details to highlight exactly what you need. As it's currently written, it's hard to tell exactly what you're asking.
    – Community Bot
    Aug 15, 2022 at 11:18
  • I had my own Time Machine issues just recently. This is how I solved it - apple.stackexchange.com/q/445273/85275 Notes: 1) This is dangerous if you do it wrong, you lose all the usual protection. 2) I don't know if it works on APFS-formatted Time Machines.
    – Tetsujin
    Aug 17, 2022 at 7:40

2 Answers 2


You don't have full access perms to a Time Machine drive by default, certainly not to 'root' levels, only to your own documents & data in the appropriate folders.

The simplest way to fully delete a Time Machine volume is to switch off Time Machine, erase the drive, then re-add to Time Machine & re-enable.

  • Actually I want to regain access to the files. Aug 15, 2022 at 11:13
  • The we'll need much more detail - which files, specifically. What format is the TM drive, what OS are you running...
    – Tetsujin
    Aug 15, 2022 at 11:17
  • The “somehow I lost permission” is carrying a lot of weight in that question I suspect.
    – bmike
    Aug 15, 2022 at 11:28
  • Plugging the TM drive in and using the TM GUI doesn't work? Aug 15, 2022 at 16:25

You never had access to delete files on the backup. You only had read access or your attempts to change permissions have broken things in an undocumented manner.

Here are some tools to free up space on time machine should you choose that path instead of letting the system delete the oldest files automatically.

However, trying to clean things manually using trash or trying to learn the command line just for this is painful for most people that ask for help here.

I recommend getting a new backup disk and use that going forward. Keep your disk you write things to separate from the one you back up makes your life much simpler. When your backup fills, archive it on a shelf and start a new backup on a clean disk.

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