Previously in Mavericks, I've been backing up my 2011 Mac Mini in time machine and restoring it to my 2010 MacBook Pro. They both have fusion drives. It has worked. Today, I Carbon Copy Cloned my Mac Mini Fusion Boot Drive to a backup external drive partition. Then I upgraded the Mini to Yosemite, and it is working fine. I backed up with time machine to another time machine partition on the external drive. Then I plugged the external drive via USB into the Macbook, and started up with CCClone partition in recovery mode. Finally, I time machine restored the new Yosemite Mac Mini Fusion backup to the MacBook Pro Fusion drive. The Macbook Pro now only starts up in recovery mode. What's going on? The SSD on the MacBookPro fusion drive is an OCZ Agility 3.