Boot Keys for Mac OS X System Start

Apr 26, 2010 - 4 Comments

Mac Boot Keys

Every Mac has a variety of optional boot functions that can be used to intervene during the OS X system startup. These are typically in the form of a single keys held down, or a press of keystrokes and hotkeys, used to issue a command and thereby adjust the booting behavior of Mac OS X. The effects are varied, and can be desirable for a wide variety of applications.

The booting keys available to Macs upon OS X system start are listed below. To use these and to gain the desired effect on the system, start holding down the appropriate key or keystroke immediately after hearing the boot chime on a Mac – that can either be booting from a cold machine, or during a system restart, just be sure to hold down the appropriate key early enough in the loading process to gain the effect, otherwise you’ll need to reboot and try again.

Mac Boot Modifications Keystrokes & Effects on OS X System Start

These will be listed as the boot keystroke followed by the effect on OS X:

  • Option – Boot directly to the Startup Disk manager
  • Command+RBoot into Recovery Mode of OS X (modern versions of OS X only)
  • C – Boot from a CD/DVD
  • T – Boot in Target Disk mode (FireWire or ThunderBolt only)
  • N – Boot from an attached network server (NetBoot mode)
  • X – Attempt to force Mac OS X to boot
  • Shift - Boot up in ‘Safe Mode’ which has limited functionality but disables third party extensions
  • Command+VBoot into Verbose mode
  • Command+SBoot in Single user mode

I find myself using all of these tricks relatively frequently in Mac centric IT work, but even for home users they may be necessary from time to time in order to perform a variety of tasks, whether troubleshooting, repairing, or just learning about a Mac.

Enjoy this tip? Subscribe to the OSXDaily newsletter to get more of our great Apple tips, tricks, and important news delivered to your inbox! Enter your email address below:

Related articles:

Posted by: Manish Patel in Mac OS X, Tips & Tricks

4 Comments

» Comments RSS Feed

  1. Juava says:

    Option key (alt) : Boot on USB device

  2. James says:

    @Juava: Actually, Alt-boot scans *all* buses (SATA, USB and Firewire on Intel Macs, IDE and Firewire on PPC Macs) and displays all bootable volumes for you to choose from. I probably use this the most.

  3. William says:

    Don’t forget Command-Option-P-R: resets the parameter ramp.

  4. last born says:

    thanks it worked for me

Leave a Reply

 

Shop for Apple & Mac Deals on Amazon.com

Subscribe to OSXDaily

Subscribe to RSS Subscribe to Twitter Feed Follow on Facebook Subscribe to eMail Updates