System Administration Guide: Basic Administration

Support for Booting Multiple Solaris Kernels

On SPARC based systems, when you type boot at the ok prompt, the default boot device is automatically selected. An alternate boot device can be specified by changing the boot-device NVRAM variable. You can also specify an alternate boot device or alternate kernel (boot file) from the command line at boot time. See SPARC: How to Boot a Solaris Kernel Other Than the Default Kernel.