I have 1 SSD disc in MacBook Pro mid 2009 with 2 partitions and I would like to make a clean installation.
So.. using Disc Utility I have erased both partitions (OS X Extended - Journaled). So far so good. Now I wanted to merge both partitions and when I do that I get "Operation failed.. Couldn't unmount disk". When I click done I see both partitions are unmounted.
When I try to merge partitions again I get instant error "The volume Macintosh HDD 1 is not journaled. To enable journaling click Enable journaling in the File menu". I did that but no luck. Still the same error.
So I gave up merging partitions and tried to install OS X. But no luck.. there is no partition to select during the installation process. Only the recovery partition is visible.
I tried to unmount discs from terminal using diskutil but none of partitions can be unmounted.
Please help me! Thank you.