Mac Maintenance: An OS X Reinstall Checklist


It was the stuff of nightmares: What I expected to be a routine repartition of my hard drive for Boot Camp became a 12-hour slog of a reinstall. My pain can be your gain, though. It’s a good idea to reinstall OS X every once and a while to keep your system running smoothly, so here are a few things to keep in mind before you begin. While most are pretty obvious, the list might prevent one or two head-smacking moments of regret.

Time Is Not On Your Side

Assuming your reinstall isn’t an emergency from a hard drive failure, make sure you have plenty of time to devote to this task. As I often joke with a friend, do not anger or tempt the Data Gods. When’s a great time to do the reinstall? On a day you have the house to yourself, and nothing else to do. When’s a horrid time to decide to do this? When you’re on deadline, late on a project, or rushed. Because when there’s little time for anything to go wrong, everything will go wrong. Depending on how much data you have, a backup, reinstall, and data restore can take you about eight hours to complete. Don’t try it if you only have four, or decide you can “deal with stuff later.” It’s never that simple.

Your Backup Is Not Good Enough

Time Machine is a fantastic feature. It’s perfect for those “oops, I deleted that file” moments, but when you’re reformatting your drive, do not place your faith in Time Machine alone. I’ve run into a few problems restoring from it (it once told me there was “one minute remaining” for around 12 hours).  External hard drives are cheap. Buy a 1TB drive and manually backup your data. What data should you be sure to backup?

Your User Folder: Music, Downloads, Documents, Pictures, etc. Don’t forget to de-authorize your iTunes account (otherwise your prior install will count towards your maximum of five machines you can authorize). Make sure you’ve got your mobile apps backed up (they’re in the iTunes folder, so if you grab that folder, you should be ok). You don’t want to lose any apps you’ve downloaded that have since been removed from the App Store (like VLC, for instance).

Applications: You don’t need to grab the whole folder, but make sure you copy your favorite apps to save time, and in case you can’t find the original install media. Grabbing Application bundles and folders will also save you the time-consuming process of re-patching software after a reinstall.

Application Support and Preferences Folders: In your ~\Library folder are two important folders to backup: Application Support and Preferences. While you can troll through them and grab what you think you need, I recommend just backing up both directories in their entirety. In these folders are any preferences or extra files an App needs. For instance, your custom templates for Pages are in \Application Support\iWork\Pages. OmniGraffle’s Stencils are also in its own Application Support folder. Preferences you may not need to grab anything from, but it’s good to make sure you’ve got a copy if an app writes data to it.

Fonts: If you use a lot of custom fonts, like I do, you might also take for granted they’re always there and overlook them. Make sure you back up that folder, too.

Preflight Checklist

Ok, now you’re sure you’ve got all your data backed up, so what else do you need before nuking your OS and starting from scratch?

Install Media and Serial Numbers: I keep all my serial numbers in the cloud on Google Docs and Evernote. Make sure you have the install media (be they discs or .dmg files) for apps like Microsoft Office, and that you have all your serial numbers in a safe place in the cloud or in hard copy.

Your Wireless Password: Remembering this can be like trying to find your birth certificate when you really need it. You’re sure it’s here, someplace, right? Make sure you can remember it, or reset it now (and write it down) while you’re still on the network.

Your Assorted Online Accounts: My bank account username is always a gotcha for me. Go through sites you access a lot and make sure you’ve got the usernames and passwords handy, since your browser cookies won’t be around to help your deficient memory post-reinstall.

Your Backups: Sure, I’ve gone into it at great length, but now’s the time to triple check you’ve backed everything up.

Good luck! Hopefully, this advice will save you a little frustration whenever you happen to reinstall OS X. Anything I’m missing? Let us know in the comments.

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