I have a Time Machine backup drive (also used for other archival purposes) which has a damaged file-system. I am able to mount it "Read Only," but fsck_hfs will not repair it. *(Apparently it's just a problem with "extended attributes," but this is enough.)

I've ordered a replacement drive, and now I need to know what is the best way to reliably copy all of the information from the old drive to the new, properly preserving permissions and everything else that Time Machine (in particular) requires. Is there, for instance, a Time Machine function to "move backup to a new drive?"

(OS/X Catalina 10.15.3, current.)

  • Yes, I saw this 2015 post: apple.stackexchange.com/questions/210424/… Feb 10, 2020 at 14:44
  • 2
    Would this help? ”Transfer Time Machine backups from one backup disk to another”: support.apple.com/en-us/HT202380
    – Alper
    Feb 10, 2020 at 14:58
  • I've used the steps in the Apple Support page linked to by @Alper to move several TM Backups to new drives.
    – IconDaemon
    Feb 10, 2020 at 18:02
  • @IconDaemon Good to hear they work. Thx for letting us know!
    – Alper
    Feb 10, 2020 at 18:08
  • ”Transfer Time Machine backups from one backup disk to another” support.apple.com/en-us/HT202380 no longer works - goes to Page Not Found
    – Mac471
    Jul 23, 2022 at 3:21

3 Answers 3


The best method to copy (if possible) a Time Machine disk hfs+ to a new one is given by Apple here : https://support.apple.com/guide/mac-help/if-the-time-machine-backup-disk-is-full-mh15137/10.15/mac/10.15

You copy the directory Backups.backupdb from the old disk to the new one by the Finder. It's very long but effective.

  • I found this page looking to copy a TM backup from one external drive to another. The link you posted applies to Catalina (macOS 10.15). If you switch the drop-down to Big Sur or Monterey, the option to copy Backups.backupdb is gone. I guess Apple thinks that it is "best" to just start a new backup. Frustrating...
    – Mac471
    Jul 23, 2022 at 3:19

I've done bunch of Time Machine transfers, and you don't want to do it the way Apple suggests.

Finder will likely spend days on preparing to transfer, and then it will fail.

Apple doesn't provide a tool to transfer Time Machine data between drives, and more importantly, they don't provide a GUI tool to reconnect that copied drive to your current files, so the next backup acts as if nothing had changed.

The only reliable way to duplicate a Time Machine drive, is with SuperDuper!. It's a looong process, but it works.

See my answer to a similar question, it should give you the info you need:

Why did this dd copy of an encrypted Time Machine drive to another drive seem to have no effect?


"Transfer Time Machine backups from one backup disk to another."


  • 1
    When answering your own quesition please take the time to enter the steps you followed as sometimes these diviate from the cited source and also the original website could change or disappear. Feb 10, 2020 at 22:12

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