ICloud – Photos media library on external hard drive

There are two main options which I would go for:

• Put your library and contents on a network volume

  This is the option that I went for on my setup, mainly because I did not consider the second option at that point in time. This option works fine for me — even when the network drops (which is pretty rare): the data transfer pauses and continues when the network reconnects.

  This works fine for my relatively large Aperture library, but I see no reason for this not to work in iPhoto.

  ✓ Easy to set up, just copy your entire library to a network drive and ⌥-launch iPhoto
  ✓ Uses no space on your local machine
  ✗ Possibly susceptible to network dropouts causing problems

• Put your library on your local machine and the contents on a network volume

  This alternative is probably better, but requires that you switch to Aperture. This way, you keep the library on your local machine but the media is stored on a network drive. This means that it uses very little space on your local machine but even if the network drops there is no chance of corruption/etc.

  ✓ Much less likely to have problems due to network dropouts
  ✓ Uses very little space on your local machine
  ✗ Does use some space on your local machine
  ✗ Harder to set up — not as simple as just copying your entire library

You could upgrade your iCloud storage and utilize the iCloud Photo Library, this can be used/setup by checking the respective box in Preferences.

The other option would be to have your Photos library on an external hard drive. Then when launching Photos, hold the option key, choose other library on the bottom left, and you can point Photos to look at the external drive's Photos library. This will only display your library when your external drive is connected however.