What does the --with-copy-persistent-files option do?

[Makavy, Erez (Erez)]

The manual says:

 

--with-copy-persistent-files=\"no\" Don't copy persistent files
                                       (or use \"yes\" to copy them).
                                       (Default: yes)

 

Copy the files to where? from where? when?

 

Thanks,

Erez Makavy