iPhoto: Sharing libraries among multiple users

You may want to be able to edit the same iPhoto library from more than one user account. If you want to do this, you must first take some steps to make sure each user has continuous read/write access to the iPhoto Library folder.

As a precaution, you may want to make a backup of your iPhoto library folder before following these steps.

To share your iPhoto library, you will need to move the folder to a volume where permissions are ignored. There are a couple of ways to do this:

Move the folder to an external drive

1. Connect an external USB or FireWire drive which has enough free space to contain the library.
2. Select this drive in the Finder.
3. Choose File > Get Info.
4. In the Get Info window, select the option to Ignore Permissions on this volume (usually selected by default).
5. Copy your iPhoto library to this drive.

Important: If you have selected this volume for use as a Time Machine backup, you will not be able to select the option to ignore permissions on the same volume. Select a different volume for the destination of your shared iPhoto library.

Keep in mind that while one user is viewing this library from iPhoto, another user will not be able to open this library at the same time. Instead, an alert message appears indicating that the library is already in use. You will need to quit iPhoto from the other user account before the next user will be able to view or edit this library.

Alternatively, move the folder to a disk image

1. Open Disk Utility from the /Applications/Utilities/ folder.
2. Choose File > New > Blank Disk Image.
3. Name the disk image.
4. Choose a large enough size from the Size pop-up menu to accommodate your current iPhoto library, plus future expansion.
5. From the Format menu choose read/write disk image or sparse disk image (recommended).
6. Save the disk image to a location where other users can access it, such as in /Users/Shared/.

The disk image should automatically mount when Disk Utility is finished creating it. If it does not, double click the image file in the Finder to mount the image. It should then show up as a mounted volume, just like any other disk.

Drag the iPhoto library folder to the disk image to make a copy of the whole library.

To point iPhoto towards this library, hold down the Option key on the keyboard when opening iPhoto. iPhoto will prompt you if you want to choose a library. Navigate to the mounted disk image and select the library you copied there.

iPhoto will now always look for the library on this disk image. You will want to make sure the image is mounted before launching iPhoto if you want to use this library. It might be a good idea to add the disk image to your Login Items to automate mounting the image every time you log in. See Mac OS X: Setting up Login, Startup items for more information.

You will need to change the permissions on the disk image to allow all users to write to it.

1. Navigate to the disk image; if you saved to the default location, locate the image in /Users/Shared.
2. Select the disk image file.
3. From the File menu, choose Get Info.
4. In the Info window, find the "Sharing & Permissions" section.  You may need to click the disclosure triangle to see the details for this section.
5. Click the lock in the bottom-right corner of the Info window. Enter an administrator name and password when prompted.
6. Under the Privlege column for "everyone," change "Read Only" to "Read & Write."
7. Close the Info window.

Note: If a user attempts to open the iPhoto library while in use by another local user, the disk image will not mount; iPhoto will instead display an alert message. Also, an alert message indicating the library is already in use appears if a local user attempts to mount the disk image remotely.