After downloading Mountain Lion (ML) and creating a bootable USB stick, using Lion Diskmaker, as my ML Install Disk, I was ready to go where many brave souls have gone before me today, upgrading my backup Lion Server to ML.

I restarted my server and selected the USB drive with ML installer, after the startup a window opened showing Install OS X Mountain Lion app. All that was now left to do was following these steps:

1. Double-clicking the **Install OS X Mountain Lion** app; a window appears, next is to click **Continue**, and then click **Agree** to agree to the software license agreement.
2. The next screen shows a list of internal startup drive where ML can be installed on. To perform a clean install on to a formated blank drive, one must click the Show All Disks button. I selected the *startup drive* that has Lion on it as I wanted to just do an upgrade.
3. Next step is to click Install, and then provide an admin-level username and password when prompted.
4. That’s is! The installer will spend some time preparing for installation. After a few minutes the installer window will show a message that the server will restart in 30-second.
   NOTE: At this point I left my server unattended as I had some other stuff to do.
5. After the restart, the actual installation occurs. This process took about 30 minutes and my server started back up running ML.

In therory this was to be it, my server was upgraded without toucing my applications and data. However, there was a very big surprise, the install was a clean install, my Lion startup disk was wipped out.

However, I did not panic for two reasons, I have a complete backup (clone) of my Lion startup disk, as well as a up-to-date Timemachine backup. And all my Documents are on the second internal harddrive.

However, instead of manually selecting from the time machine my app data, such as all my mail accounts and content, I decided to restore my server back to Lion, and do another upgrade, this time watching more closly what caused the installer to do a clean install instead of an upgrade.

So, stay tuned for more on this in a day or two.