boot system

This command activates the specified image. It will be the active-image for subsequent reboots and will be loaded by the boot loader. The current active-image is marked as the backup-image for subsequent reboots. If the specified image doesn't exist on the system, this command returns an error message. The optional unit parameter is valid only in Stacking, where the unit parameter identifies the node on which this command must be executed. When this parameter is not supplied, the command is executed on all nodes in a stack.

Format boot system [unit] {active | backup}
Mode Privileged EXEC