Symptom
All indicators on controller B are off. The indicator on controller A is normal.
The application server connected to controller B cannot send read and write requests to the storage device, causing service interruption. Log in to DeviceManager. On the Performance Monitoring page, the write I/O traffic or read I/O traffic of the host port on controller B becomes 0.
Impact Scope and Degree
If UltraPath is not installed, host services are interrupted due to a controller fault. You can manually switch to a normal controller to restore host services.
Fault Diagnosis
Figure1 Troubleshooting flowchart for a Fibre Channel link failure
