Sun Microsystems Netra 1290, Administration Manual

Page: 123 / 146

Appendix B Watchdog Timer Application Mode 105
■
If the application watchdog is enabled and you break into the OpenBoot PROM
by issuing the
break
command from the system controller’s
lom
prompt, the SC
automatically disables the watchdog timer.
Note – The SC displays a console message as a reminder that the watchdog, from
the SC’s perspective, is disabled.
However, when you re-enter the Solaris OS, the watchdog timer is still enabled
from the Solaris Operating System’s perspective. To have both the SC and the
Solaris OS view the same watchdog state, you must use the watchdog application
to either enable or disable the watchdog.
■
If you perform a dynamic reconfiguration (DR) operation in which a system
board containing kernel (permanent) memory is deleted, then you must disable
the watchdog timer’s application mode before the DR operation and enable it
after the DR operation. This is required because Solaris software quiesces all
system IO and disables all interrupts during a memory-delete of permanent
memory. As a result, system controller firmware and Solaris software can not
communicate during the DR operation. Note that this limitation affects neither
the dynamic addition of memory nor the deletion of a board not containing
permanent memory. In those cases, the watchdog timer’s application mode can
run concurrently with the DR implementation.
You can execute the following command to locate the system boards that contain
kernel (permanent) memory:
sh> cfgadm -lav | grep -i permanent
■
If the Solaris Operating System hangs under the following conditions, the system
controller firmware cannot detect the Solaris software hang:
■
Watchdog timer’s application mode is set.
■
Watchdog timer is not enabled.
■
No rearming is done by the user.
■
The watchdog timer provides partial boot monitoring. You can use the
application watchdog to monitor a domain reboot.
However, domain booting is not monitored for:
■
Bootup after a cold poweron.
■
Recovery of a hung or failed domain.
In the latter cases, a boot failure is not detected and no recovery attempts are
made.
■
The watchdog timer’s application mode provides no monitoring for application
startup. In application mode, if the application fails to start up, the failure is not
detected and no recovery is provided.