Installation guide

loading, and so on. At the conclusion of the main initialization tasks

(process 0), init (process 1) starts an additional set of tasks that

includes reading the /etc/inittab ﬁle, acting on instructions

found there, and executing the relevant run command scripts. These

scripts contain entries that initiate activities such as mounting and

checking ﬁle systems, removing temporary ﬁles, initializing the

clock daemon, initializing the network daemon, setting up printer

spooling directories and daemons, enabling error logging, and

performing other tasks speciﬁed within the scripts or in related

directories. At the conclusion of these activities, the system is

enabled and accessible to users.

The Tru64 UNIX operating system allows you to boot an alternate kernel.

For example, if you cannot boot your system, you could boot /genvmunix

to troubleshoot the problem with your system. You could also boot an

alternate kernel to test new drivers or to add options to the existing kernel.

3.2 Preparing to Boot Installed System

As the system administrator, you set up or encounter various preboot or

postshutdown states. This section describes and recommends procedures

for preparing and initiating a reboot from a variety of system states. The

states discussed here include the following:

• A powered-down system

• A powered-up, halted system

• A powered-up system in single-user mode

• A crashed system

_______________________ Note _______________________

If the system is running in single-user mode and you want to

use the ed editor, you must change the protections of the root

ﬁle system to read-write. At the prompt, enter the following

command:

# mount -u /

3.2.1 Preparing to Boot a Powered-Down System

A system is powered down when the hardware (processor, devices, and

peripherals) is turned off. Administrators power down the hardware

periodically for routine maintenance or to conﬁgure new devices.

Starting Up and Shutting Down the System 3–3