OS X El Capitan: The Missing Manual

The Homemade Installer Disk

El Capitan’s download-only shtick is revolutionary and, in most cases, incredibly convenient. But sometimes, you’ll miss having a physical disk with the installer on it. You might wish you had one if, for example, you want to install El Capitan on a huge array of Macs, like the ones at a school or in a business; downloading that 6-gig installer over and over again would drive you crazy.

You might also wish you had an installation disk for when your Mac starts acting up and the tricks described in Appendix B don’t seem to work.

As it turns out, you can make an El Capitan installation disk fairly easily. All you need is a hard drive or a flash drive (8 GB or larger); the Install OS X El Capitan.app program that winds up in your Applications folder when you first get El Capitan (see the box on Reinstalling: Tricks of the Trade); and the free DiskMaker X app on this book’s “Missing CD” page at www.missingmanuals.com.

Note

DiskMaker X is free, quick, and easy. But there’s a more technical way to build the installer disk, too, using a Terminal command that Apple has built right into OS X. For the instructions, visit http://j.mp/1OOafTf.

Open DiskMaker X, and click the El Capitan button. Click either “An 8 GB USB thumb drive” or (if you’re using a hard drive) “Another kind of disk.” The following screens ask you to choose the disk or partition that will become your installer—and warn you that that disk is about to be erased.

When the process is complete, you wind ...