Photos library files
I just recently upgraded my Macbook Pro to Yosemite. I also got the update for iPhoto, so it works in the new OS. I have noticed a second file that is being created when I import my older iPhoto library into Photos. What is that file and how do I deal with it when doing backups? Do I need the original iPhoto library file AND the newly created 2nd file if I plan to only use iPhoto? Can the 2nd file stand alone and be used by photos- or do I need both? Thanks.
iMac, OS X Mavericks (10.9.1), Also iPad2, MBP (10.10.4), iPhone 4