The chassis process (chassisd) could not read back information from the Chassis Management Bus (CMB) about the indicated component (field-replaceable unit, or FRU).

The problem related to this syslog message is described in the following sections:

The CHASSISD_CMB_READBACK_ERROR message is logged when the chassisd process is not able to read information from the component stated in the message.

When there is a read error on the Chassis Management Bus, it logs the action into the syslog. Below are some examples of the message:

The cause for such a notification can be due to a hardware state condition.

Use these command outputs to see if any of the system components are reporting errors:

It may also be possible to keep track of the errors being reported in the PFE with this command:

If the message refers to an FPC or FEB, then obtain the logs from the FPC/FEB to see what errors they are recording on the component itself. This can be done with one of the following sets of commands:

Be sure to replace the [fpc#/scb#] entry above with the reference to the system component that is reporting the log message.

Follow these troubleshooting steps to work towards resolution of the issue:

  1. Check the messages and chassisd outputs to see if any components are reporting errors in association with the CHASSISD_CMB_READBACK_ERROR message.
  2. Reserve a maintenance window to offline and online the suspected component(s) to force a reset.
  3. If the issue still remains, reseat the component(s) in their slots.
  4. See if it is possible to swap the component with an identical unit in the system, or with a spare.

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