I have mac mini 2011. 8gb ram and stock HD. I have partitioned the HD in 2 equal parts of 10.7 and 10.9. My printer Samsung ml2510 needs 10.7 and won't use 8 or 9. So I have to keep 10.7. I'm downloading Yosemite as we speak. No errors it started downloading. Now assuming it finishes no errors. What should I do. Can I repartition the 2 to in 3 parts. Or should I just upgrade on top of 10.9. Or for the full Yosemite experience is a fresh install better. Is there any way to back up the whole OS and move it to an external. Or just archive it. Last time I checked CCC and SD were no longer free. Then I could wipe out the 10.9 and install Yosemite on the other partition. Or if I just erase 10.9 are there any things that work on 10.9 but not on Yosemite yet. I don't play games. I have a WII for that. And no photoshop for me either. Thanks.