Synch one external hard drive to another - iTunes media library backup question
Hello,
What's the best way to synch one external hard drive to another ?
My hard drive recently crashed. One expensive data recovery later, I'm setting up my iTunes media library in two different external hard drives, so as to avoid this ever happening again.
Does anyone have any ideas? I won't be keeping either hard drive plugged all the time. Ideally I'd like to back up one hard drive every month or so. Is there a nifty piece of software out there that will only back up what is newly added to the first one?
Thanks,
Noel
MacBook Pro, OS X Yosemite (10.10.5)