I've been using iPhoto since many versions ago ... probably since version 1. In that time, the file structure of its iPhoto Library has changed a few times, and I suspect that some of the files in there now are no longer needed. I'd like to clean it up to save disk space. Do you know if the following are needed?

  1. The root level of the iPhoto Library contains some folders named after years, from 1998-2006. Each folder contains subfolders for months and days, and each day folder contains a data folder and then two numbered files, one with no extension and one with the .attr extension. These files are only about half a kilobyte in size and appear to contain metadata only. It looks like a version upgrade in 2006 made these obsolete since they're all older than that.
  2. A Caches folder contains two files with long alphanumeric names, last modified in 2009.
  3. A Contents folder contains a PkgInfo file, last modified in 2008.
  4. An Auto Import folder is empty, last modified in 2008.
  5. A Dir.data file, last modified in 2008.
  6. Files named Library.data, Library.iPhoto, Library6.iPhoto and Library6.iPhoto.back, last modified in 2009.
  7. A ThemeCache file, last modified in 2010.

It seems pretty clear these are no longer used; I could always delete them and find out, since I have a backup. But maybe someone who started using iPhoto after 2009 can tell me if any of these files are in their library?

2 Answers 2


I quit iPhoto, deleted all the files and folders I listed above, and restarted iPhoto. After browsing through a bunch of old photos and albums, I don't see any problems. I'll keep my backup for a while, and post back here if I see any problems later.

  • 1
    Six months later and I haven't seen any problems with iPhoto after deleting those files.
    – arlomedia
    Commented Oct 19, 2012 at 15:59

It is a bad idea to try to manually modify the folder structure inside the iPhoto library, as you seem to want to do.

The best way is to follow Apple's instructions for rebuilding the iPhoto library.

However, this is usually only used as a repair procedure if iPhoto is malfunctioning.

You can try this, but make sure you have a complete backup of your iPhoto library before you start the rebuilding procedure.

Also, realize that iPhoto has an internal Trash that is separate from Mac OS X's Trash. If you have deleted hundreds of photos over the years, and never emptied the iPhoto Trash, those photos will still be in there and taking up space in the file structure.

  • My version of iPhoto doesn't have the "Repair the iPhoto Library Database" option shown on the support link above, but it does have a "Reclaim unused disk space from databases" option. I tried that, along with rebuilding all the photo thumbnails; none of the other options seemed relevant. After this process finished, I still had all the same old files.
    – arlomedia
    Commented Apr 4, 2012 at 23:45
  • Exactly which version of iPhoto do you have?
    – user9290
    Commented Apr 5, 2012 at 3:49
  • 8.1.2 - iPhoto '09! I've kept my OS up to date, now running Lion ... I assumed the iLife applications were getting upgraded along with it, but apparently not. But that's another issue.
    – arlomedia
    Commented Apr 9, 2012 at 3:15

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