Let's start with the basics: I bought a 2012 Macbook Pro 15" 2.3GHz. I upgraded it with 8GB of ram, and I bought a Sandisk Extreme 240GB SSD. I also bought an optibay drive caddy. I have been having one hell of a time trying to get the SSD to work. From my original 500GB Apple HDD, I backed it up to an external drive. I put the SSD into the caddy and put it into the ODD slot. I booted up MountainLion installer, went into disk utility, and it wouldn't let me format the SSD. I put it into the HDD bay (no HDD or ODD in, just SSD) and it let me format. I restored from the backup to the SSD, then replaced it into the caddy and into the ODD bay. It wouldn't boot. I could see it in disk utility, but wouldn't even let me verify or repair the disk. this thing is making me so frustrated. Now for my explanation. I want the HDD in the HDD bay because of the more shielding and protection. Thus, the SSD in the ODD bay. Am I doing anything wrong? Can anybody lend me some thoughts or ideas as to how to get this to work? Thanks!