Logic - back up the content already on an external hard drive on another external hard drive

I am saving hard drive space on my limited internal hard drive and use an external hard drive for all Logic content but also all my 3-th part libraries and samples. I would like to have a back up of this external drive just in case. But I would like to be able to access it at any time, meaning I could use both drives not at the same time but with different occasions . The problem could be that Logic and the 3-th part plug ins content might get confused and ask me to relocate from scratch to the new drive. I am considering using the exact same name on both external drives. Not sure it will work. Any ideas? Thank you.