Every time the Mac operating system gets an update, I ask myself – do I want to upgrade, or do I want to do a fresh install? Ever since around Snow Leopard (OS X 10.6), the Upgrade & Install process has been fairly painless, and now that Migration Assistant doesn’t crash in the middle of the file transfer, it’s pretty easy to do an Erase & Install with all your data brought over from your Time Machine backup.
But those who know me know that I rarely do things the easy way. For the update from Mavericks to Yosemite, I decided to do it the hard way – a clean Yosemite install on an empty hard drive, and a manual transfer of data.
Why did I put myself through this? The main reason I decided on a fresh install was actually for work purposes. I use my personal computer for web development, and I had several versions of PHP, MySQL, and command-line tools installed on my hard drive. Every now and then, I’d run into a conflict that interfered with my workflow. It was much easier for me to install Mac OS X on a completely empty hard drive (a newly-striped RAID-0 pair of SSDs) and re-install my web development tools than it was to work out the existing problems plus any additional conflicts brought on by a new operating system.
Mentally, starting fresh makes it feel like you have a new computer – you get to decide what applications you install (no more lingering preference files from incompatible software!), what settings you want to change (new desktop backgrounds to choose from!), and what files you really need or don’t need to copy over.
But make no mistake – a clean install is not easy, and it is a very long process. If you want to undertake it, here are some tips and tricks to make the process a little bit easier.
1. Back Up Your Computer
This may seem like an obvious one when you’re about to erase your hard drive, but please, make sure everything is backed up. I even made myself a second Time Machine backup on a portable hard drive that I kept in my laptop bag. This came in handy when I needed to copy over some files at work.
2. Prepare Your Data
Outside of backing up, there are two things you should do on your existing system. First, de-authorize any software that might be tied to your computer with limited licenses, especially iTunes since it has a limited number of authorized computers (iTunes deauthorization instructions can be found here). Second, make sure you have the serial numbers of any software that needs to be re-installed. Use 1Password (App Store link, currently a free download) to easily store all of your software serial numbers and your website logins, and sync it with Dropbox (or another cloud sync service). Syncing your logins with 1Password means they will all be immediately available on your new computer (after you re-install 1Password and Dropbox – so don’t lose your Dropbox login). Logins can also be saved via iCloud Keychain Sync. After this, you’re ready to install Yosemite.
3. Download the OS X Yosemite Installer and DiskMaker X
You cannot do an Erase & Install by running the installer from your boot drive, you must either install it on an external hard drive, or create a bootable install disk from a USB flash drive. I did the latter, which was a piece of cake.
Download the Yosemite installer (App Store link, about 20 minutes), but do not run it. Download DiskMaker X (free/donation), and when you launch it, it will walk you through turning your USB drive into a Yosemite installer (about 10 minutes).
Restart your computer and hold down the Option key, and select your install disk as the startup drive.
Upon launch, go to the Utilities menu and use Disk Utility to erase your existing hard drive. Make sure you have at least one backup of your data before you do this!
Exit Disk Utility to return to the Yosemite installer and install the new OS.
4. New User, Same as the Old User
When the installer has finished (about 15 minutes), the computer will prompt you for various setup tasks, including user account creation. Make the user’s ‘short name’ the same as it was on the previous system. The ‘short name’ is used for file permissions, so to avoid any permissions conflicts, it’s best if your username is the same as before.
5. System Setup
Continue Apple’s guided setup, and then when it is finished, set up your ‘new’ computer however you want! Go through System Preferences and change the settings to what you used to use. Among other things I change, I set the scrollbars to always show, I turn on automatic login (though for a laptop, it’s best to keep automatic login off), and I fix the mouse scroll and key-repeat speeds.
TinkerTool is a great application for changing some of the preferences that are set just beneath the surface of Mac OS X. Alternative apps that do essentially the same thing are OnyX and Secrets, and all three are free.
6. Install Apps and Migrate Data
Use your main App Store account to download any software you have previously purchased through Apple. A yearly, $20 MacUpdate Desktop subscription can also help you keep track of purchased third party software, and keep that software up-to-date. Have 1Password handy to look up your serial numbers.
It’s time to copy your data over manually. Plug in your Time Machine backup drive, but do not choose it as a Time Machine drive just yet. Open the drive in the Finder and go to the Backups.backupdb/[ComputerName]/Latest/ folder to get to the root of your backed up hard drive.
If anything requires libraries or specific preference files, copy those files before opening the application for the first time. For example, don’t let iPhoto create a new, empty iPhoto Library – copy your current library first! Other preferences and related files will be found in the ~/Library/Preferences/ and ~/Library/Application Support/ folders of your backup. Copy those to the ~/Library/Preferences/ and ~/Library/Application Support/ folders on your Yosemite drive.
The rest of your personal data should just live in your backup drive’s Documents folder, though you may also have files on the desktop or in Downloads. If you store any files outside of these three folders, I suggest moving them into Documents; go ahead and drag the content from those folders to their new homes on the Yosemite drive. If you have a lot of stuff on your hard drive, just let this run overnight. (I don’t even know how long it took my 150 gigabytes worth of photos to copy over USB, but it was done by the next morning.)
7. Enjoy Your “New” Computer
Your computer now has a fresh start. It has the latest version of all the software on it, and there are no files lingering from old systems or old applications. And hopefully, instead of just copying everything over, you were able to do some “Spring Cleaning” of your personal files.