Mac users are probably more familiar with the concept of soft links, also known as “symbolic links.” Mac users would recognize the idea of a soft link from the long-time Mac concept of aliases 1. Photos uses Unix-style hard links when importing iPhoto libraries. I had an inkling that this was all happening due to a feature of OS X that I believe has previously only been used by Apple in Time Machine, and prodded by TidBITS reader Bryan Walls, I confirmed it this morning. What is this magic? How can it not duplicate the photos, yet not risk losing all your data if you were to throw away your old iPhoto library? The Photos import process is friendly when it comes to disk space - it doesn’t duplicate the photos it imports from iPhoto and Aperture, so you don’t lose precious storage space. The (hard) link between Photos and iPhotoĪs I wrote my TidBITS article about the initial beta release of Photos for OS X, I was struck by how iPhoto imports work, which I described like this:
