Logical Volumes on RedHat 7.3

Hello,

I have a scenario whereby I have a RedHat 7.3 server where it was built and all the space went to root.

What I mean is that there are no logical volumes for /usr /var /opt and so forth. I do have them for /home and /tmp.

It is a small development server with 20GB that has grown over time.
Here is how my logical volumes look.
/dev/mapper/rhel_wpdev3v-root
/dev/mapper/rhel_wpdev3v-home
/dev/mapper/rhel_wpdev3v-tmp

I have a /backup folder that is taking up most of the space.
What I am hoping to do is to add additional space to the server, then create logical volumes and specifically a LV called /backup along with /usr /var etc.

So here is my question, will the kernel/OS know to place the /backup (root/backup folder) to the Logical volume /backup and will it do it automatically for me.

I have never tried this before so any advice/help/pointers will be greatly appreciated.

Thank you,
Patrick