If you need to install OS X El Capitan on multiple Macs, a bootable install drive is more convenient if you have a slow internet connection as you will just need to download the 6.21GB once.
If your Mac is experiencing problems, an emergency disk with the OS X installer on a thumb drive is useful – I would also pack it with your favourite diagnostic tools such as Disk Warrior, Onyx, Cocktail or TechTool.
I admit to not using many of these like I used to, as OSX has shrugged off many of the problems of the past. Additionally, most of my data is in the cloud and I have a robust backup protocol in relation to my usage.
Here are the steps from Apple Support’s “Create a bootable installer for OS X” (08 Oct 2015):
- Download the OS X installer from App Store – this is the longest part, depending on your internet connection. Quit the Application which will startup automatically.
- Plug in your 8GB (or larger) flash drive – rename it as “MyVolume” – exactly as this, with no space, follow the caps
- Open the Terminal App (in your Applications Folder) and paste this exact command and press enter:
sudo /Applications/Install\ OS\ X\ El\ Capitan.app/Contents/Resources/createinstallmedia –volume /Volumes/MyVolume –applicationpath /Applications/Install\ OS\ X\ El\ Capitan.app
- It will ask if you wish to erase the disk; check that the volume name specified is indeed “MyVolume”, and then say yes. Enter your password as prompted. This takes a few minutes and you are done!
This is an update to last year’s five steps – the installer now erases and makes the USB disk an OS X Extended disk.