So like a doofus, ive never really done encryption on any of my PCs/drives. With the way stuff is going, now I want all of it encrypted. The issue is I have so much data from over the years and everything ive read says it deletes everything when you encrypt.

For me it would mostly be my desktop and my nas.

Is it really a matter of, I'm gonna have to buy a whole bunch more HDDs to copy everything over to, encrypt, copy it all back? What's the best (Linux) software for a mass copy task like that to be sure it works correctly?