Restore back-up from pre-encrypted drive into newly encrypted drive

It sounds like I am going to be reinstalling CentOS 7 on a server this weekend.

The original installation didn't have the drive encrypted and it needs to be done. My understanding is that this will require a reformat so was going to back-up with rsync to a USB drive and restore after the fresh install and the drive being encrypted.

Is this permitted? Just wasn't sure if CentOS will allow a complete back-up from a un-encrypted file system to restored to an encrypted one.