I don't need to backup my whole disk but I want to backup my Photos once a month. From what I've read, Time Machine seems to work amazingly well so I was hoping for a similar solution for Photos.

I want to be able to delete the Photos library on my internal drive but keep the files "alive" on an external one. I use the "new" photos app introduced like half a year ago and migrated my library back then accordingly.

It would be perfect if I could do that with 2 separate external drives.

Is there any software that gets this job done? Maybe even something from Apple? Most stuff I find wants you to backup to iCloud or doesn't really go with the user deleting the files off his internal drive.

Thanks in advance.

EDIT: El Capitan, MacBook Air 2013, the external drives both are NTFS but I would also accept reformatting them if that was necessary. I use 3rd party drivers for NTFS access which work fine for me.

  • If the reason you are using NTFS is to access the drives from Windows computers, then if you have to switch to HFS+ you can still keep using them on Windows computers by installing an HFS+ driver on the Windows machine(s).
    – Fiksdal
    Commented Jan 25, 2016 at 10:48

1 Answer 1


You will need an external drive formatted Mac OS Extended (Journaled) to use as a Time Machine backup. TM cannot use a NTFS formatted disk as the backup destination.

Unfortunately, Time Machine cannot use an NTFS drive as a backup source, either. Time Machine relies on the Mac OS Extended (Journaled) file system on all drives acted on to do its work. (This isn't strictly true as you can create and backup to sparsebundle files on a network drive mounted with NTFS, but this is not in the scope of your question.)

Thus you need two Mac OS Extended (Journaled) external drives - one for the TM backup; one for the Photos Library. If you know how to use Time Machine, you can stop reading. If not, keep going.

In System Preferences > Time Machine, Click the Select Disk... button and choose this external disk for Time Machine backups. One the disk is selected, click the Options... button at the lower right, which brings up the window where you can exclude items from backups. Normally, all connected disks (internal & external) are backed up, except for the Time Machine disk. You can drag (or click the + sign) and add Macintosh HD (or whatever else you may have named the boot HD) to the list of excluded items. This will enable you to backup only the external HD with the Photos library.

  • 1
    Assuming your internal hard disk is still called Macintosh HD, of course.
    – nekomatic
    Commented Jan 25, 2016 at 10:42
  • Edited to include nekomatic's info-nugget.
    – IconDaemon
    Commented Jan 25, 2016 at 10:46
  • But if I now delete the Photos Library on the internal drive and run Time Machine, wouldn't the Photos on the external drive get lost then because while syncing the Mac "thinks" I don't need them any longer? Commented Jan 25, 2016 at 11:25
  • This Apple Tech Note shows how to define a default (System) Photos Library. Use this to set the external drive with the Photos Library to be the default location when Photos.app opens. I'm not sure what you mean by "...the Mac "thinks" I don't need them any longer?"
    – IconDaemon
    Commented Jan 25, 2016 at 12:19
  • But when I set the default library to the external drive I won't be able to transfer pictures without having the drive attached. I mean what happens to photos that I delete from my internal drive - when I delete a file that is also represented in a backup, it will be gone the next time I back up, otherwise backups would end up huge. How can I make sure I don't encounter the same behavior with Photos? Commented Jan 25, 2016 at 13:05

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