I have two partitions on my 2012 iMac (fusion drive). First partition is Mavericks, second is Bootcamp running Win 7. If I do an upgrade (not a clean install) from mavericks to yosemite, will I have any issues? I've heard some issues with bootcamp not being bootable after upgrade to yosemite-but I think this has been when a third partition was made (mavericks, yosemite, bootcamp). I would be staying with just two partitions after the upgrade: yosemite and bootcamp. Feedback? Thanks!