Sun Microsystems Sun Fire V440 Diagnostics And Troubleshooting Manual page 192

Doing this results in the loss of all system coherence and state information. A
manual system reset could corrupt the server's file systems, although the fsck
command usually restores them. Use this method only when nothing else works.
Caution – Forcing a manual system reset results in loss of system state data and
should be attempted only as a last resort. After a manual system reset, all state
information is lost, which inhibits troubleshooting the cause of the problem until the
problem reoccurs.
Important: Accessing the ok Prompt Suspends the
Solaris Operating Environment
It is important to understand that when you access the ok prompt from a
functioning Sun Fire V440 server, you are suspending the Solaris operating
environment and placing the system under firmware control. Any processes that
were running under the operating environment are also suspended, and the state of
such processes might not be recoverable.
The diagnostic tests and commands you run from the ok prompt have the potential
to affect the state of the system. This means that it is not always possible to resume
execution of the operating environment from the point at which it was suspended.
Although the go command will resume execution in most circumstances, in general,
each time you drop the system down to the ok prompt, you should expect to have to
reboot the system to get back to the operating environment.
As a rule, before suspending the operating environment, you should back up files,
warn users of the impending shutdown, and shut down the system in an orderly
manner. However, it is not always possible to take such precautions, especially if the
system is malfunctioning.
For More Information
For more information about the OpenBoot firmware, see the OpenBoot 4.x Command
Reference Manual. An online version of the manual is included with the OpenBoot
Collection AnswerBook that ships with Solaris software.
174 Sun Fire V440 Server Diagnostics and Troubleshooting Guide • July 2003