So, now you want to move to OSX Mountain Lion.

I’m not kidding, I’m word-for-word copying this old post because little nothing has changed, and you feel a need to read this.

Want to move to OSX Mountain Lion? Concerned? Be Safe:

  1. Make sure you have a Time Machine backup. If you don’t have a time machine backup, you’re a fool.
  2. Make sure your machine can actually run OSX Mountain Lion, “iMac (Mid 2007 or newer), MacBook (Late 2008 Aluminum, or Early 2009 or newer), MacBook Pro (Mid/Late 2007 or newer), MacBook Air (Late 2008 or newer), Mac mini (Early 2009 or newer), Mac Pro (Early 2008 or newer), Xserve (Early 2009).” No, your G5 will still not run OSX Mountain Lion
  3. Use SuperDuper or CarbonCopyCloner to make a clone of your existing system out to another hard drive. Buy an external drive, or buy a drive dock and buy bare drives to plug into it. Docks are great for Time Machine backups too. Do not whine that hard drives are expensive. How much is your time worth to you?
  4. Buy and download the OSX Mountain Lion Installer. Don’t pirate it, for fuck’s sake. It’s only $30 $20. Save a copy of the Installer somewhere safe, make an installable DVD or USB Key while you can.
  5. If you’re using Filevault 1, turn it off (and you should be using Filevault, if you’re using a portable machine). It’ll make transitioning easier, and you’ll want to enable the “whole disk filevault” after Mountain Lion is installed. If you’re using Filevault 2 (the Filevault introduced in Lion 10.7), you can leave it enabled – OSX Mountain Lion can install to an existing whole-disk-encrypted volume without any problems.
  6. Install OSX Mountain Lion to the SuperDuper’d Drive and not your internal drive. Don’t do anything to your internal drive.
  7. (alternately: install OSX Mountain Lion to the internal drive, and disconnect your SuperDuper’d drive for safety. This is more work to get back to normal though for when your OSX Mountain Lion goes wrong.)
  8. Boot from the drive you put OSX Mountain Lion on (the SuperDuper’d drive)
  9. Find out exactly how many Rosetta apps you didn’t know you have. Start looking for replacements, since Rosetta is dead. PowerPC has been dead for years. Move with the times. I’m also looking at you, stupid developers still shipping PowerPC code
  10. Use it like this for a few days. Try out everything you normally use to find out it doesn’t work anymore. Keep track. Nicely ask developers to get OSX Mountain Lion versions out.
  11. If it doesn’t work out, don’t worry. Just boot from your untouched Snow Leopard Lion drive, carry on as if nothing happened. If you fuck things up, use your Time Machine backup to save your ass.

Did that all turn out nicely? Fine. Your choice at this point:

  • Install OSX Mountain Lion to your regular drive
  • SuperDuper your external clone drive with OSX Mountain Lion back to your internal drive. Disconnect external drive and keep it safe.

Make sure to keep your Time Machine backup for when you need to roll back.

Never work without a net.