CentOS

I have inherited Centos 7 servers that were build with one single file system. I am getting them hardened but I'm not sure how to set various directories to noexec and nodev since they are not their own filesystems. I've read some articles regarding the use of the bind directive with mount. I however have not been able to get this to work. Can someone lay it out for me.

Am I better off adding a new disk (the are VMs) and partitioning the various directories with lvm on that new disk?

Thank you in advance

No one can help with this?

I'd be inclined to re-install.