A Short Guide on How to Install Mountain Lion

With Apple’s Mountain Lion being released today, we thought it would be a good idea to write a short blog on best practices with regards to installing Mountain Lion. This is not a complete guide but, more of a installation check list of pre and post tasks that should be considered as part of your installation strategy.

Pre-installation Checks:-

1. What are the system requirements for installing Mountain Lion?

  • OS X v10.6.8 or later
  • 2GB of memory
  • 8GB of available space
  • Some features require an Apple ID; terms apply.
  • Some features require a compatible Internet service provider; fees may apply.

and supported models are:

  • iMac (Mid 2007 or newer)
  • MacBook (Late 2008 Aluminum, or Early 2009 or newer)
  • MacBook Pro (Mid/Late 2007 or newer)
  • Xserve (Early 2009)
  • MacBook Air (Late 2008 or newer)
  • Mac mini (Early 2009 or newer)
  • Mac Pro (Early 2008 or newer)

Apple have published a technical specifications page which can be found here.  The main thing to remember is that although the minimum specs say you need 2GB of memory, I would recommend a minimum of 4GB of memory.

2. Purchasing and downloading Mountain Lion

Ever since Mountain Lion’s predecessor, Lion (10.7), Apple have changed the distribution model for delivering their operating systems to you which is now in the form of a digital download via the App Store. This is all well and good as long as you have a fast and reliable internet connection, even then, people (including myself) have run into problems with getting the download to complete in a sensible amount of time.
I have previously experienced starting a download of Lion and seeing an estimate of 145 hours to complete the download! My resolution to this was to change my DNS settings to use OpenDNS or Google’s DNS servers instead of my local ISP’s DNS.
Another time where I still experienced problems when previously it had worked by changing DNS, my resolution was to plug my laptop directly into my router rather than going through my network switch.
It should be noted that while Apple are all for this new App Store purchase and download model, they do understand that this does not work for everyone and as such have made the software available via a handy USB thumb drive. Unfortunately I haven’t yet seen a OS X Mountain Lion USB Thumb Drive on Apple’s Online Store but hopefully it should be available soon for you to order.

3. Pre-installation Maintenance

If you’re like me, you’re probably impatient and would like to get Mountain Lion downloaded and installed as quickly as possible. However it makes good sense to run some maintenance checks ahead of installing as it can save you a world of pain, either during installation or post installation.
Your pre-installation checks should include:-
Check the compatibility of your existing Applications that you intend to run under Mountain Lion.

  • I use the website Roaringapps.com as a reference for checking my installed applications. Your process should be to navigate to the app, single-click the app to select, and then select File>Get Info to check the exact version of your app.
  • It’s a good idea to have a list or spreadsheet of all of your essential apps and version numbers so that you can check the compatibility using the website mentioned above.
  • Run Software Update on your existing 10.6 or 10.7 installation and applying any updates found.
  • Verify your Startup Disk using Disk Utility and Repair where necessary.
  • Verify your Disk Permissions using DiskUtility and Repair where necessary.

4. Backup you existing hard drive data.

With any major OS upgrade, it is important to backup your data. You can use whatever backup method you feel comfortable with, (i.e Time Machine) but personally I prefer to make a disc image of my hard drive using Disk Utility, which encapsulates all of you hard drives data (including invisible files, preserving permissions) single DMG file that you can store on a external backup hard drive.

5. Installing Mountain Lion

In general there are two basic installation types, Upgrade and Clean Installation.
Performing an upgrade to Mountain Lion is by far the easiest and quickest way of getting your system upgraded and ready to use with all of your original data and settings. Why people choose not to perform this type of installation is down to choice, technical level, condition of your existing system, and dare I say it, patience!
There are numerous websites detailing how to install Mountain Lion, below are a couple of guides by Tom Nelson of About.com regarding these typical installation types of upgrading and clean installing Mountain Lion.
How to Perform a Clean Install of OS X Mountain Lion on a Startup Drive
Upgrade Install of OS X Mountain Lion