How to prepare your Mac for OS X 10.8 Mountain Lion

Apple's next major operating system upgrade is just around the corner, making the upcoming days a perfect time to prepare.

Topher Kessler MacFixIt Editor
Topher, an avid Mac user for the past 15 years, has been a contributing author to MacFixIt since the spring of 2008. One of his passions is troubleshooting Mac problems and making the best use of Macs and Apple hardware at home and in the workplace.
Topher Kessler
5 min read

Apple's next release of OS X "Mountain Lion" is slated for release by the end of this month, with some recent developments suggesting it may be out by as early as next week. If you are thinking about upgrading your Mac to the new operating system, then you might consider reserving some time this weekend to ensuring your system is capable of and prepared for the upgrade.

While for the most part you should be able to download and install the upgrade without any problems, there are a few things you can do to help prevent running into odd problems.

Ensure your Mac meets the requirements
As with the move to OS X Lion, this next upgrade has some advancements that will leave out some older Mac hardware. In this case, the requirements primarily revolve around graphics capabilities and support for the system's 64-bit kernel. As we previously reported, Apple has an official list of supported hardware, so if your computer is one of the following systems then, it will not be able to run Mountain Lion:

System Profiler
You can see your system's model number in this field in the system profiler/information utility (click for larger view). Screenshot by Topher Kessler/CNEt
  • iMac6,1 or earlier (polycarbonate cases)
  • MacBook4,2 or earlier
  • MacBookPro2,2 or earlier
  • MacBookAir1,1 or earlier
  • MacMini2,1 or earlier
  • MacPro2,1 or earlier
  • XServe2,1 or earlier

To look up these model numbers, go to the Apple menu and choose About this Mac, and then click the More Information button. If you are already running Lion, then the system should show you the model's time frame that you can compare to Apple's official list; however, if not, then click System Report and you will see the system information tool open. In the Hardware section of the tool, check the Model Identifier and compare it to the list above. If the model is the same or smaller as those in the list (e.g., MacBookPro2,1), then it will not run Mountain Lion.

The next requirement for the upgrade is to have access to the Mac App Store for the purchase, which requires at least OS X 10.6 to be installed and upgraded to its latest version. If you currently have OS X 10.5 on your system, then you will need to purchase Snow Leopard and install it before you can upgrade. While Apple does have an up-to-date program for those who have purchased new Mac hardware, it has so far made no mention about those who have just purchased Snow Leopard or Lion.

A final component of hardware requirements is RAM. Many of the systems that support running Mountain Lion were shipped with 2GB of RAM, which is the minimum amount of RAM recommended for running the new OS. The more RAM you have in your system the better, so if you can be sure to upgrade to at least 4GB, but preferably 8GB or more.

Back up your system
If you do not have a backup routine set up on your system, then you might take advantage of this weekend to do so. Get a spare hard drive and enable Apple's Time Machine backup routine to make a fully restorable backup of your system. Apple's Time Machine is not the only option for this, and you can use a number of system cloning tools like SuperDuper and Carbon Copy Cloner for making mirror copies of your boot volume.

Clear up resolvable issues
As we use our systems, various odd problems may crop up, including slowdowns, application freezes and crashes, or other unwanted behaviors. Before upgrading to Mountain Lion, try clearing up as many of these as possible. Running a general maintenance routine on your system may help by clearing out caches and other temporary items, and also go to Software Update and install any updates for your version of OS X. In addition, be sure to fully update any third-party software as developers will be releasing updates to work with Mountain Lion's new sandboxing and security technologies.

While you can do your best to address crashes and other problems you might be experiencing, if you cannot address them then do not let that stop you from updating. Often an update may clear up such problems, so do what you can to fix them beforehand, but then try the upgrade anyway. As long as you have a full system backup, then you can restore your system from it should anything go wrong.

Optionally create a Mountain Lion installation drive
Starting with Lion Apple's preferred delivery method for the OS upgrade is through its online store; however, you can still create a boot disk from the install package. We previously outlined how to do this with OS X Lion so be sure to read those instructions for doing so. The process for Mountain Lion should generally be the same:

Mountain Lion restore install volume
If you get errors when restoring the InstallESD image directly, then first mount it and restore the mounted volume to your desired external drive (click for larger view). Screenshot by Topher Kessler/CNET
  1. Purchase and download Mountain Lion from the Mac App Store.
  2. Quit the installer when it automatically launches.
  3. Locate the installer in your Applications folder.
  4. Right-click the installer and choose "Show Package Contents."
  5. Go to the Contents > Shared Support folder.

In the Shared Support folder you will see an disk image called "InstallESD.dmg," which contains all the files to boot to the OS X installer and upgrade your system. You can use Disk Utility to restore this image to an external drive as was the case with Lion. However, in doing so you may run into a couple of differences. First, you will likely need a drive that is larger than most standard 4GB USB drives, and second, you might get an error when restoring the disk image file directly to the external drive. If you get an error, then first mount the image by double-clicking it, and then drag the mounted "Mac OS X Install ESD" volume to the "Source" field when restoring it to the destination drive of choice (thanks to MacFixIt reader Michael A. for outlining this option).

Consider waiting
As a last word of note, consider waiting on upgrading. Mountain Lion has some attractive advancements that will have many people immediately downloading it on its first day out of the cage. This inevitable rush gives you the opportunity to wait and see if any outstanding bugs managed to get by the testing process. Apple rigorously tests the OS with developers in its volunteer testing program, but even so it cannot account for all situations and bugs will undoubtedly slip by. With past OS releases, Apple has quickly issued updates to address various problems, so you might wait until version 10.8.1 or 10.8.2 is released before installing it on your system.

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Watch our hands-on First Look of Mountain Lion:

First Look
Watch this: OS X Mountain Lion