> We want to move our log and spool directory to a NAS (Network Attached
> Storage) to pave the way for a fail-over system, iÍve found in system.cfg
> the place to do so along with the strong recommendation to against making
> changes there.

I don't understand how moving only the log and spool directories to a NAS is going to allow fail-over operation. In a fail-over setup, the log directory is typically local to the server whereas just about everything (including the spool directory but, even more importantly, the main directory, list archive directories, etc) is shared. You should be putting the whole directory tree on NAS.

  Eric