Enabling Or Disabling The Openboot Environmental Monitor; Automatic System Shutdown - Sun Microsystems Sun Fire V480 Administration Manual

Enabling or Disabling the OpenBoot
Environmental Monitor
The OpenBoot environmental monitor is enabled by default whenever the system is
operating at the ok prompt. However, you can enable or disable it yourself using the
OpenBoot commands env-on and env-off. For more information, see:
"How to Enable OpenBoot Environmental Monitoring" on page 160
"How to Disable OpenBoot Environmental Monitoring" on page 160
Note – Using the Stop-A keyboard command to enter the OpenBoot environment
during power-on or reset will immediately disable the OpenBoot environmental
monitor. If you want the OpenBoot PROM environmental monitor enabled, you
must reenable it prior to rebooting the system. If you enter the OpenBoot
environment through any other means—by halting the operating system, by
power-cycling the system, or as a result of a system panic—the OpenBoot
environmental monitor will remain enabled.

Automatic System Shutdown

If the OpenBoot environmental monitor detects a critical overtemperature condition,
it will initiate an automatic system shutdown sequence. In this case, a warning
similar to the following is generated to the system console:
WARNING: SYSTEM POWERING DOWN IN 30 SECONDS!
Press Ctrl-C to cancel shutdown sequence and return to ok prompt.
If necessary, you can type Ctrl-C to abort the automatic shutdown and return to the
system ok prompt; otherwise, after the 30 seconds expire, the system will power off
automatically.
Note – Typing Ctrl-C to abort an impending shutdown also has the effect of
disabling the OpenBoot environmental monitor. This gives you enough time to
replace the component responsible for the critical condition without triggering
another automatic shutdown sequence. After replacing the faulty component, you
must type the env-on command to reinstate OpenBoot environmental monitoring.
Chapter 4 Network Interfaces and System Firmware 59