Info on cp –preserve=links

I’m trying to understand what cp --preserve=links does when used by itself, from my tests it seems that it copies a normal file normally and dereferences symlinks, but it seems like it just has the same effect as cp -L when used on a single file.

How to check progress of running cp?

Is it possible to check the progress of running cp process? Some processes respond to various KILL signals so that you can check what is their status. I know that I can run cp with parameter -v but what if forgot to do that, cp is running for a very long time and I want to know which file is being copied, or how many were already copied.