Sun Fire V445 Server Administration Guide - SCN Research

If the kernel hangs and the watchdog times out, ALOM reports and logs the event
and performs one of three user configurable actions.
■ xir: this is the default action and will cause the server to capture cpu register
and memory contents to the dump-device using the firmware level sync
command. In the event of the sync hanging, ALOM falls back to a hard reset
after 15 minutes.
Note – Do not confuse this OpenBoot sync command with the Solaris OS sync
command, which results in I/O writes of buffered data to the disk drives, prior to
unmounting file systems.
■
■
Reset: this is a hard reset and results in a rapid system recovery but diagnostic
data regarding the hang is not stored, and file system damage may result.
None - this will result in the system being left in the hung state indefinitely after
the watchdog timeout has been reported.
For more information, see the sys_autorestart section of the ALOM Online Help.
About Automatic System Restoration
Note – Automatic System Restoration (ASR) is not the same as Automatic Server
Restart, which the Sun Fire V445 server also supports.
Automatic System Restoration (ASR) consists of self-test features and an autoconfiguring
capability to detect failed hardware components and unconfigure them.
By doing this, the server is able to resume operating after certain nonfatal hardware
faults or failures have occured.
If a component is one that is monitored by ASR, and the server is capable of
operating without it, the server will automatically reboot if that component should
develop a fault or fail.
ASR monitors the following components:
■ Memory modules
■ PCI cards
If a fault is detected during the power-on sequence, the faulty component is
disabled. If the system remains capable of functioning, the boot sequence continues.
Chapter 8 Diagnostics 195