MacOS – What happens after OS X Internet Recovery without erasing disk

Reboot your Mac. When you hear the boot chime, hold the COMMAND + R keys. You will enter the Lion Recovery environment. From there, simply choose to reinstall Lion. It will simply remove the current system and replace it with a fresh copy. None of your data will be deleted or moved. The only thing that will be replaced will be the core system files. There is no longer any need to make backups, migrate your data, or mess with partitioning.

If you'd like to read more about the Lion Recovery function, go here: http://support.apple.com/kb/HT4718

Basically you have a CoreStorage Logical Volume Group without a CoreStorage Logical Volume now. You may delete your Logical Volume Group (-> step 4) or restore a Logical Volume (-> step 7).

Requirements: Booted to Recovery Mode

1. Please quit Disk Utility.
2. Open Utilities/Terminal in the menubar

3. Enter diskutil cs list and hit enter. The output will look like this:

   CoreStorage logical volume groups (1 found)
   |
   +-- Logical Volume Group 5B8350BF-20EF-4199-82E6-129EFF19E9EB
       =========================================================
       Name:         Macintosh HD
       Status:       Online
       Size:         250640592384 B (250.2 GB)
       Free Space:   6111232 B (6.1 MB)
       |
       +-< Physical Volume 907FCDE2-0C62-4951-A39E-36F19244FDB7
       |   ----------------------------------------------------
       |   Index:    0
       |   Disk:     disk0s2
       |   Status:   Online
       |   Size:     250634481152 B (250.2 GB)
   

4. To delete the Logical Volume Group enter:

   diskutil cs delete lvgUUID 
   

   The lvgUUID is the UUID of the Logical Volume Group and usually the first listed.
   In the above example:

   diskutil cs delete 5B8350BF-20EF-4199-82E6-129EFF19E9EB
   

   This will delete your CoreStorage LVG and reformat it as an unencrypted HFS+ volume.

5. Enter exit, hit enter and quit Terminal
6. Open Disk Utility to format your disk like you want.

7. After step 3 you may create alternatively a new CoreStorage Logical Volume in your orphaned LVG by entering:

   diskutil cs createVolume lvgUUID jhfs+ NewVolName Size
   

   Using the above example

   diskutil cs createVolume 5B8350BF-20EF-4199-82E6-129EFF19E9EB jhfs+ MyMac 100%
   

   would create a new full sized (≈ 249.5 GB) Journaled HFS+ volume with the name 'MyMac'