Hi, I have a 2012 Mac Pro running Lion (10.7.5) as my primary OS - mainly so I can continue to use FCP7. I've taken a separate installed 2TB internal drive, made a partition on that drive, and loaded Mavericks on it so I can go back and forth between Lion and Mavericks. I would now like to upgrade this 'Mavericks' partition to Yosemite so that I can run the latest Adobe CC and AVID offerings from that partition - is it possible? Is it advisable? My trepidation comes from the fear that upgrading the second drive will 'somehow' disrupt Lion which I still use on a day to day basis - so far things with Mavericks on the other drive are just fine, but one never knows. Figured this would be the best place to ask about it. Thank you very much in advance, Matt.