New IMac 27"with dual internal hard drives

Install OS X on the SSD:

Install or Reinstall Lion/Mountain Lion from Scratch

Be sure you backup your files to an external drive or second internal drive because the following procedure will remove everything from the hard drive.

Boot to the Recovery HD:

Restart the computer and after the chime press and hold down the COMMAND and R keys until the menu screen appears. Alternatively, restart the computer and after the chime press and hold down the OPTION key until the boot manager screen appears. Select the Recovery HD and click on the downward pointing arrow button.

Erase the hard drive:

1. Select Disk Utility from the main menu and click on the Continue button.

2. After DU loads select your SSD volume (usually Macintosh HD) from the left side list. Click on

the Erase tab in the DU main window.

3. Set the format type to Mac OS Extended (Journaled.) Optionally, click on the Security button and set the Zero

Data option to one-pass. Click on the Erase button and wait until the process has completed.

4. Quit DU and return to the main menu.

Reinstall Lion: Select Reinstall Lion/Mountain Lion and click on the Install button. Be sure to change the target disk to your SSD.

Note: You will need an active Internet connection. I suggest using Ethernet if possible because it is three times faster than wireless.

After you boot from the SSD open Users & Groups preferences. Click on the lock and authenticate. CTRL- or RIGHT-click on the user account and select Advanced Options. You will see a Home Dir: field with a Browse button on the right. Click on the button. Navigate to the HDD's Users folder. Select your account folder then click on the Open/Choose button. You must restart immediately.

Upon the restart your SSD system will now be using your actual Home folder located on the HDD. You can then go about installing your applications or copying them from the HDD to the Applications folder on the SSD (and also from the Utilities folder on the HDD to the one on the SSD.) You will likely need to do some transfers of the Applications Support and Preferences folders found in the main Library folder.

If you don't do what I outlined, then you can create an alias on the SSD to the folder of data on the HDD. There are many options for setting this up. Maybe you need to do a Google search where you can find links about the various alternatives and configurations.

HI Kappy,

Thanks for outlining this procedure. I am in the process of creating an SSD with HDD hybrid in my iMac. So o nice I have the SSD installed and yosemite installed on it, I am planning to format the HDD to wipe it clean and then will use it for a target drive for my files. So a couple questions regarding this:

1. Does an OS need to be installed into that HDD or just use as a mac os journaled volume?

2 I know how to point my iTunes and iPhoto to the HDD. But how to point other folders to it, such as documents, iCloud Drive, or local drop box folders?

3 Finally, is time machine a backup option for both drives? In other words, will all content from both drives be backed up and accessible from time machine or will I need to point that in two directions as well?

thnaks much in advance.

I've used this guide before for moving my iTunes library to a separate HDD

Move Your iTunes Library to a new Location

Seems to work well.

Tom

Thanks Tom. I already know how to move the iTunes and iPhoto libraries.