Edit: I originally asked this in terms of forcing TM to do a "full" backup. After getting answers about how every backup is a "full" backup, I realized I asked the wrong question. The problem is that I have a backup that I don't trust, on a disk that has other stuff on it, including TM backups from other machines. I'd like to do another backup of one of my machines, independent from the first one. Below is the rest of my original question.

I've looked all over, and there just doesn't seem to be a way to do this. Lots of people taking guesses that seem to work in some cases, but not in mine. I've tried just deleting the folder that contains the backup, but of course the finder won't let you delete it, or even rename it. Bash won't allow it either -- it always says "operation not permitted". Is there really no way just to make TM do a second, independent backup to the same disk without reformatting it?

  • 1
    Do you mind if I ask why? Oftentimes knowing your purpose can help us find an alternative solution if necessary.
    – user24601
    May 8, 2016 at 21:09
  • The directory of the last backup is a full backup Time Machine just does not have to copy all the data
    – mmmmmm
    May 8, 2016 at 21:11
  • @user24601 Glad to explain why, just didn't think it was ok to put it in the question. So: Time Machine says my Time Capsule has gone south on me. So I took another spare drive and did a backup to it, with the intention of reformatting the Time Capsule. But the backup went so quickly that I don't trust it. I want to do another one. I can't reformat the spare drive, because there's a backup on it from another machine. And I don't have any other spares. May 8, 2016 at 21:17
  • @Mark I guess I'm using the wrong terminology. I'd like to do a backup in which Time Machine does copy all the data. May 8, 2016 at 21:19
  • The first TM backup to a new destination will always be a full backup (as are, technically, all the others). Did you check whether the size of the backup folder seems to be similar to your main drive?
    – nohillside
    May 9, 2016 at 4:35

4 Answers 4


Every backup is a full backup. Your destination has hard links to each file so that if you copy any snapshot to another volume or folder - you have a copy of every file. If you delete a file from one time interval - the other intervals lose no data. As implemented, there is no reason to store duplicate bits on e destination if a hard link suffices to fully document each file being backed up.

  • This is true, but assumes that the backup drive doesn't have any issues.
    – Alger
    May 9, 2016 at 18:31
  • 1
    @Alger that is true of all backups
    – mmmmmm
    May 9, 2016 at 18:38

Use Disk Utility to create a new partition and point Time Machine to that.


If you want to do a mirrored backup use something like rsync or Carbon Copy Cloner.

Time machine's mission is to make incremental backups every hour so you can browse and restore old versions of your documents. It wouldn't be my choice for making a full mirrored backup of a hard drive.

Rsync is built in to OSX so the price is right and it can synchronize two folders or whole drives.

Good luck!


In your situation, I'd try doing a backup with Super Duper.


It will be a full backup, can go on any drive with enough free space for the backup, and takes you away from any possible issues with Time Machine.

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