Sun Microsystems Netra 1290, Administration Manual

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103
A P P E N D I X
B
Watchdog Timer Application Mode
This appendix gives information on the watchdog timer application mode on the
Netra 1290 server.
This appendix provides the following sections to help you understand how to
configure and use the watchdog timer and to program Alarm3:
■
“Understanding the Watchdog Timer Application Mode” on page 103
■
“Watchdog Timer Unsupported Features and Limitations” on page 104
■
“Using the ntwdt Driver” on page 106
■
“Understanding the User API” on page 106
■
“Using the Watchdog Timer” on page 107
■
“Programming Alarm3” on page 110
■
“Watchdog Timer Error Messages” on page 112
Note –
Once the application watchdog timer is in use, it is necessary to reboot the
Solaris operating system in order to return to the default (non-programmable)
watchdog timer and default LED behavior (no Alarm3).
Understanding the Watchdog Timer
Application Mode
The watchdog mechanism detects a system hang, or an application hang or crash,
should they occur. The watchdog is a timer that is continually reset by a user
application as long as the operating system and user application are running.
When the application is rearming the application watchdog, an expiration can be
caused by:
■
Crash of the rearming application