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Delete Time Machine Backups of Computers You No Longer Own

Time Machine is a great way to save your ass when something goes wrong with your Mac. And I know there’s a lot of ass-saving to do when you’ve recommended Macs to every one, like I have. So I force my friends and family to get an external hard drive, at least the same size as the internal hard drive to make Time Machine backups with.

Now, let’s say you’ve had your Mac for a while and decide to get a new Mac or upgrade your OS a full version number? If you migrate all your settings to the new environment, including your  Computer Name and Hard Drive Name, then no problem. When the computer asks you if you’d like to continue using the external drive for Time Machine backups, go ahead and confirm that. Time Machine should add the new backups to the existing hierarchy of backups.

But what if you didn’t migrate every setting and you’ve already started making Time Machine backups. What if you realized this 3 months down the road? Most likely, your external hard drive will fill up faster than your internal hard drive because you now have DOUBLE BACKUPS.

Now, there might be a way to merge backups, but today, we’ll explore deleting the old backups of a computer and hard drive that no longer exists under the same name. Because you probably don’t need both backups of the Applications, Library, or System folder.

***UPDATE*** This method may not work with Time Machine backups on an Apple Time Capsule, as each users’ backups are encoded into a SparseImage.

The safe way to delete files and folders from a Time Machine backup is from within Time Machine using the Gear menu. But you’ve probably noticed that those old backups will not show up when you “Enter” Time Machine. That’s because Time Machine thinks that you’re on a totally different computer and you have no right accessing backups from another computer. Ah, but it IS (was) the same! It’s your computer.

To “Enter” an Time Machine backup of a computer under a different name. You’ll need to:

  1. Open System Preferences > Time Machine
  2. Check “Show Time Machine Status in Menu bar”
  3. Option-click the Time Machine icon in the top right of the menu bar and select “Browse Other Time Machine Disks”
  4. Select the backup under the old computer name
  5. Click “Use selected Disk”
  6. Travel backwards using the date ruler or arrows to the desired file/folder
  7. Select the file/folder to delete
  8. From the Gear menu, you may select to A) Delete the item or B) Delete ALL backups of the item
  9. When you’re done, hit the Esc key

You have safely and successfully deleted un-necessary files from your old Time Machine backup.

*** Update *** For more in depth information on troubleshooting Time Machine backups, there is an excellent site by Pondini.

Posted in Apple, English.


12 Responses

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  1. Perry Kneisel says

    Worked great! Thanks! Got a new external HD (not my backup HD) to replace my old external used for storing photos only. Once plugged in (WD plug and play), my backup drive kept showing my old external HD as well as my new external HD. Copied all photos to the new external HD and set it up to be backed up in Time Machine. But Time Machine HD kept backing up my old external HD as well even though it was not connected. Waste of space. Used your directions and the old drive went away along with its backups.

  2. olwarpaint says

    This works great for deleting a single instance, but i’d like to know how you could select a range of backups from the old computer. In my case, I have old business computers that I have backed up, and I only want to keep the latest backup from them, deleting all the previous ones to free up space.

  3. Celia says

    > olwarpaint
    Time Machine takes incremental versioned backups of your computer, therefore, does not hold duplicate backups if a file was never changed. But for those files that are updated often, this arrangement does not make it easy to drop and delete older versions of those files.

    If you want only the most recent versions of files, you may archive them somewhere else by taking a backup of the most recent Time Machine image onto another storage media. If it is something you don’t need to access a lot, I’d recommend you burn a DVD.

  4. Albert says

    Hi,
    I have tried it, but it does not work. My situation is not the similar. I have a son who has gone away to school and I want to delete his back-ups from the Time Capsule. I tried the steps, but I only saw my back-ups and not his.

    Can you please advice? Thanks!

  5. tach says

    The “Browse Other Time Machine Disks” button does not appear in my menu. Perhaps, because Time Machine thinks that the backup is from an entirely different computer. Thus I am stuck. Has anyone else had this problem and found a solution?

  6. Celia says

    Albert,
    Your situation does sound different. You have a TimeCapsule where you and your son backed up files to and now your son moved away with his computer? If your son’s computer does not show up in the “Other computers” list, then he might have already deleted his files. If his files are still on the TimeCapsule’s hard drive, then there’s a chance he didn’t use the TimeMachine backup to store those files there. He may have just copied them there manually. Ask him to clean up after himself when he comes home for break.

  7. Celia says

    Tach,
    Are you pressing the option key? You will see the “Enter Time Machine” item toggle to “Browse Other Backup Disks” with the option key.

  8. paul says

    When I do this, I do not see backups of other machines either.

  9. Chris says

    FYI – you do NOT option+click on the Time Machine icon. You click on the icon, the menu drops down, then press option.

  10. Celia says

    Maybe something is different on your computer, but it does not matter when you press the option key. You can even toggle between the choices by pressing/releasing the option key while you click-and-hold the Time Machine icon in the menu bar.

  11. HM says

    I have the same issue. I simply don’t see backups of any other machines regardless of when I option click Time Machine. We have 3 Macs getting backed up to the same Time Machine. I am trying to solve the EXACT same issue that this otherwise well written article is designed for! Please help

  12. Celia says

    Added a link for Pondini’s extensive Time Machine Troubleshooting guide.
    http://pondini.org/TM/Home.html

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