I've got a 2011 iMac with the factory-installed SSD/HDD combo. I've been running a DIY Fusion drive for awhile; it works spectacularly. I installed by 1) formatting both drives, 2) setting up the Fusion drive, 3) doing a fresh install of Mountain Lion to create the recovery partition, and then 4) restoring from my clone. When I look in diskutil, I see that there's a recovery partition labeled "Boot OS X" on both drives; on the 2 TB HDD, that partition is 650 MB. Not a huge deal, obviously, but I'm unclear why the second drive needs it. Do other DIY Fusion drive users have recovery partitions on both drives?