[Koha] upgrading

Hi, Its beginning to sound like there are enough changes in the Koha beta that its worth doing an upgrade. I was scanning through the INSTALL file for the "right way" to do this and noticed this line: perl Makefile.PL --prev-install-log /path/to/koha-install-log which I assume is a way of me avoiding having to remember what I answered for all the install questions before. The only problem is I can't find it. Does anyone know where this file is usually put? -custard