If I use my drive to backup with time machine will it erase the files that I have on there? (It's a 1TB drive that already has about 600GB occupied)
I can't make a partition in the drive (something about its specifications) and I want to have a backup before I update to macOS Mojave.
MacBook Pro 13", macOS 10.13
It won't erase the drive, but I wouldn't risk doing that without other backups of your important information in case something goes wrong. The drive also would have to be formatted Mac OSX Extended Journaled to use TM. And you would also need to make sure it's large enough to handle what on your computer.
Also, if you are referring to using your internal drive that you are booted from, that's not a good idea. And depending on your internal drive type, probably may not work anyway. It wouldn't be large enough anyway for the amount you have on it.
The backup should be on a separate drive.
Time Machine BackUp
