I don't need to backup my whole disk but I want to backup my Photos once a month. From what I've read, Time Machine seems to work amazingly well so I was hoping for a similar solution for Photos.
I want to be able to delete the Photos library on my internal drive but keep the files "alive" on an external one. I use the "new" photos app introduced like half a year ago and migrated my library back then accordingly.
It would be perfect if I could do that with 2 separate external drives.
Is there any software that gets this job done? Maybe even something from Apple? Most stuff I find wants you to backup to iCloud or doesn't really go with the user deleting the files off his internal drive.
Thanks in advance.
EDIT: El Capitan, MacBook Air 2013, the external drives both are NTFS but I would also accept reformatting them if that was necessary. I use 3rd party drivers for NTFS access which work fine for me.