Sun Microsystems Sun Fire V490 - Manual (Page 49)

Chapter 2 System Overview 21
The power subsystem is monitored in a similar fashion. Polling the power supply
status registers periodically, the monitoring subsystem indicates the status of each
supply’s DC outputs.
If a power supply problem is detected, an error message is displayed on the system
console and logged in the /var/adm/messages file. Additionally, LEDs located on
each power supply are illuminated to indicate failures.
Automatic System Recovery
To some, automatic system recovery (ASR) implies an ability to shield the operating
system in the event of a hardware failure, allowing the operating system to remain
up and running. The implementation of ASR on the Sun Fire V490 server is different.
ASR on the Sun Fire V490 server provides for automatic fault isolation and
restoration of the operating system following non-fatal faults or failures of these
hardware components:
■ Processors
■
Memory modules
■
PCI buses and cards
■ FC-AL subsystem
■ Ethernet interface
■ USB interfaces
■ Serial interface
In the event of such a hardware failure, firmware-based diagnostic tests isolate the
problem and mark the device (using the 1275 Client Interface, via the device tree) as
either failed or disabled. The OpenBoot firmware then deconfigures the failed device
and reboots the operating system. This all occurs automatically, as long as the Sun
Fire V490 system is capable of functioning without the failed component.
Once restored, the operating system will not attempt to access any deconfigured
device. This prevents a faulty hardware component from keeping the entire system
down or causing the system to crash repeatedly.
As long as the failed component is electrically dormant (that is, it does not cause
random bus errors or introduce noise into signal lines), the system reboots
automatically and resumes operation. Be sure to contact a qualified service
technician about replacing the failed component.
MPxIO
Multiplexed I/O (MPxIO), a feature found in the Solaris 8 Operating System, is a
native multipathing solution for storage devices such as Sun StorEdge™ disk arrays.
MPxIO provides: