128 Module removal and replacement3. Check the system status and event logs to verify that the system is stable.4. Replace the partner controller as described in these instructions.Configuring partner firmware updateIn a dual-controller system in which PFU is enabled, when you update firmware on one controller, the systemautomatically updates the partner controller. Disable partner firmware update only if requested by a servicetechnician.Use the CLI to change the PFU setting.IMPORTANT: See the topic about updating firmware within the Storage Manager Guide before performing a firmwareupdate.NOTE: The CLI provides an option for enabling or disabling Partner Firmware Update for the partner controller asdescribed in the Storage Manager Guide. To enable or disable the setting via the CLI, use the set advanced-settingscommand, and set the partner-firmware-upgrade parameter. See the CLI Reference Guide for more informationabout command parameter syntax.Verifying component failureSelect from the following methods to verify component failure:• Use the SMC to check the health icons/values of the system and its components to either ensure that everythingis okay, or to drill down to a problem component. The SMC uses health icons to show OK, Degraded, Fault, orUnknown status for the system and its components. If you discover a problem component, follow the actions inits Recommendation field to resolve the problem.• As an alternative to using the SMC, you can run the show system CLI command to view the health of thesystem and its components. If any component has a problem, the system health will be Degraded, Fault, orUnknown. If you discover a problem component, follow the actions in its Health Recommendations field toresolve the problem.• Monitor event notification — With event notification configured and enabled, use the SMC to view the eventlog, or run the show events detail CLI command to see details for events.• Check Fault LED (back of enclosure on IOM face plate): Amber = Fault condition.• Check that the OK LED (back of enclosure) is off.Stopping I/OWhen troubleshooting disk drive and connectivity faults, stop I/O to the affected disk groups from all hosts as adata protection precaution. As an additional data protection precaution, it is helpful to conduct regularly scheduledbackups of your data.IMPORTANT: Stopping I/O to a disk group is a host-side task, and falls outside the scope of this document.When on-site, you can verify that there is no I/O activity by briefly monitoring the system LEDs; however, whenaccessing the storage system remotely, this is not possible. Remotely, you can use the showdisk-group-statistics command to determine if input and output has stopped. Perform these steps:1. Using the CLI, run the show disk-group-statistics command.The Reads and Writes fields show the number of these operations that have occurred since the statistic was lastreset, or since the controller was restarted. Record the numbers displayed.
