Looking for some suggestions on the best approach to make a another back up of my Photos library that is pushing 100 gigs. Currently on El Capitan 10.11.1 and using Photos. I'm currently using Time Machine on an External Lacie USB3 drive as my primary backup, but want to make another backup on a different external drive to be on the safe side. I'm currently not backing up to the Cloud (and I'm not sure I want to given the size of the library). A couple of options I'm investigating: 1. Can I copy the photos library file to another external drive? I've done this before for iPhotos. Does this work with Photos in El Capitan. 2. Make another Time Machine backup on a new External. Is this an option? How do you keep in sync? Suggestions??