If you want to, you can remove the actual Time Machine backup files from the drive in question yourself, or even format the drive to be Mac compatible and wipe it completely clean of any other data. This also does not turn off Time Machine. Additionally, manually started Time Machine backups will also no longer go to the removed drive when it is connected.Īgain, this does not delete any of the data from the Time Machine drive, it simply stops backing up to the drive that has been removed. The removed drive will no longer be part of the Time Machine backup chain, meaning when it’s connected to the Mac it will no longer trigger the automatic backup process. Exit out of System Preferences when finished.Confirm that you want to remove the drive from Time Machine and stop backing up to the disk in question.Select the hard drive, disk, or backup volume that you want to remove from Time Machine backups, then click on “Remove Disk”.Go to the Time Machine system preference panel, then scroll down in the drive list to find “Add or Remove Backup Disk” and click that.Pull down the  Apple menu and choose ‘System Preferences’.

Note that you do not need to have the drive connected to the Mac to remove it from Time Machine, this process is the same in all versions of OS X:

Deleting a Hard Drive from Time Machine Backup to Stop Backups to That Drive from a Mac

Backup external hard drive time machine