Interpreting the POST results

About this task

Each time the switch is powered on, rebooted, or reset, the switch performs a power-on self-test (POST). Total boot time with the POST can be several minutes. The POST can be omitted after subsequent reboots by using the fastboot command or entering the diagDisablePost command to persistently disable the POST. The success or failure results of the diagnostic tests that run during POST can be monitored through LED activity, the error log, or the command line interface. During the POST, the LEDs flash different colors.

The POST includes the following tasks:
  • Conducts preliminary POST diagnostics.
  • Initializes the operating system.
  • Initializes hardware.
  • Runs diagnostic tests on several functions, including circuitry, port functionality, memory, statistics counters, and serialization.

Perform the following steps to determine whether POST completed successfully and whether any errors were detected.

Procedure

  1. Verify that the LEDs on the device indicate that all components are healthy. If one or more LEDs do not display a healthy state:
    1. Verify that the LEDs are not set to "beacon" (this can be determined through the switchShow command or Web Tools).
    2. Follow the recommended action for the observed LED behavior.
  2. Verify the diagShow command displays that the diagnostic status for all ports in the device is OK.
  3. Review the system log for errors. Errors detected during POST are written to the system log, which can be viewed by using the errShow command.
Parent topic: Monitoring the Device