Every few years, I find it necessary to wipe my computers and do a clean install of the operating system. As a developer and a power user, I install a lot of software. The cumulative effect of in­stal­la­tions and upgrades is to leave a lot of cruft on the machines. Entropy increases and the machines grow slower and perhaps less reliable. So I like to wipe the hard disk, install a new operating system, and reinstall only those apps that I know I need.

My mid-2012 MacBook Pro came with OS X 10.7. Shortly thereafer, 10.8 was released and I promptly upgraded; likewise with 10.9. Yosemite (10.10) was released in October 2014, but I held off switching until now, as I knew I wanted to do a clean install, which meant setting aside a sizeable block of time.

I backed up everything during the week, over and above my normal backups of external drives, CrashPlan, Dropbox, and GitHub. I made a list of all the apps that I care about and of various settings. And I prepared a bootable thumb drive with the OS X Yosemite Installer app.

Last night, I inserted the thumb drive into the USB slot. I restarted the machine while holding down the Option key, which brought me to a boot menu. I used Disk Utility to erase the partition and then I installed Yosemite.

And then I spent many hours installing apps I care about and restoring data.

I’ve been a fan of the Homebrew package manager for several years. It does a great job of installing and updating developer-related tools for use at the command line. Last year, I learned about a sister project, Homebrew Cask, which takes of installing graphical ap­pli­ca­tions. Instead of down­load­ing DMGs, I used Cask to install a number of apps.

I discovered Caskroom Fonts last night, which took care of installing most of the fonts I care about. One exception: I wanted to install Consolas and some of the other C* fonts from the ClearType Font Collection, without installing Microsoft Office. It’s possible to do that via Microsoft’s Open XML File Format Converter for Mac.

My 2½-year-old machine feels faster and more responsive after the clean install. I upgraded my late-2013 work MacBook Pro to Yosemite a couple of months ago, without seeing a difference in per­for­mance, so I attribute the im­prove­ment to getting rid of a lot of crap.