Specifications

62 Chapter 5 Setting General System Preferences
To set how long the system waits to restart after a power failure:
$ sudo systemsetup -setwaitforstartupafterpowerfailure seconds
To see if the system is set to restart after a system freeze:
$ sudo systemsetup -getrestartfreeze
To set the system to restart after a system freeze:
$ sudo systemsetup -setrestartfreeze (on|off)
Changing Power Management Settings
You can use the pmset tool to change power management settings, including:
 Display dim timer
 System sleep timer
 Wake on network activity
 Wake on modem activity
 Restart after power failure
 Dynamic processor speed change
 Reduce processor speed
 Sleep computer on power button press
You configure settings for power modes using pmset. There are four pmset flags:
To set the disk sleep timer for all modes of operation:
$ sudo pmset -u disksleep minutes
To display the settings in use:
$ sudo pmset -g
For more information, see the pmset man page.
Parameter Description
seconds Must be a multiple of 30 seconds
Flag Description
-a Applies the power settings to all.
-b Applies the power settings to battery operation.
-c Applies the power settings to the charger (wall power).
-u Applies the power settings to the Uninterruptible Power Supply (UPS).
Parameter Description
minutes Must be a multiple of 30 seconds