Mac OS X v10.6 Snow Leopard system requirements Then, determine if your Mac meets ALL minimum system install requirements. This step is really needed in case something goes wrong with the install of the new OS or you simply do not like the new OS, you have a very easy way/procedure to return your Mac to its former working state. Then, use either OS X Time Machine app to backup your entire system to the external drive OR purchase, install and use a data cloning app, like CarbonCop圜loner or SuperDuper, to make an exact and bootable copy (clone) of your entire Mac's internal hard drive. Before embarking on a major OS upgrade, it would be wise, advisable and very prudent if you backup your current system to an external connected and Mac formatted Flash drive OR externally connected USB, Thunderbolt or FireWire 800, Mac formatted hard drive.
