Technical data

Fabric OS Administrator’s Guide 9-1
Publication Number: 53-0000518-09
Chapter
9
Working With Diagnostic Features
This chapter provides information on diagnostics and how to display system, port, and specific
hardware information. It also describes how to set up system logging mapping (syslogd) and how to set
up the offloading of error messages (supportSave).
The purpose of the diagnostic subsystem is to evaluate the integrity of the system hardware.
Diagnostics are invoked two ways:
• Automatically during the power-on self test (POST)
• Manually using Fabric OS CLI commands
The error messages generated during these test activities are sent to the serial console and system
message logs, whose output formats may differ slightly.
Use the diagHelp command to receive a list of all available diagnostic commands.
Refer to the Fabric OS Command Reference Manual for a complete description of each command.
Viewing Power-On Self Test
By default, when you power on the system, the boot loader automatically performs power-on self tests
and loads a Fabric OS kernel image.
The POST tests provide a quick indication of hardware readiness when hardware is powered up. These
tests do not require user input to function. They typically operate within several minutes, and support
minimal validation because of the restriction on test duration. Their purpose is to give a basic health
check before a new switch joins a fabric.
These tests are divided into two groups: POST1 and POST2. POST1 validates the hardware
interconnect of the device, and POST2 validates the ability of the device to pass data frames between
the ports. The specific set of diagnostic and test commands run during POST depends on the
switch model.
POST1 cannot be bypassed and runs from the boot loader. The factory default configuration is also set
to run POST2, but you can configure your switch to bypass POST2, which runs after the kernel image
has started but before general system services such as login are enabled.
Although each test performed during POST2 is configurable, you should only modify a POST2 test if
directed by your switch provider’s customer service representative.
You can use the diagDisablePost command to disable POST2, and you can reenable it using the
diagEnablePost command. Refer to the Fabric OS Command Reference Manual for additional
information about these commands.