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Controller Failure in a Non-UltraPath Environment
A fault on controller B interrupts services when UltraPath is not installed. In this case, manually switch the application server connections from controller B to controller A to ensure service continuity.
Symptom
- All indicators on controller B are off. Indicators on controller A are normal.
- Read and write requests from the application servers connected to controller B cannot be sent to the storage system, causing service interruption. On the Performance page of the DeviceManager, the write or read I/O traffic on the front-end port of controller B becomes 0.
Possible Causes
The controller is faulty.
Impact
If a controller is faulty and host services are interrupted when UltraPath is not installed, you can manually switch the host services to another functional controller.
Fault Diagnosis
Figure 5-27 Flowchart for handling service interruption caused by a fault in controller B in a non-UltraPath environment
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Procedure
- Switch services from controller B to controller A.
- Remove the cable between controller B and the application server.
- Connect the application server to controller A.
- Reconfigure the initiator of the host where services are interrupted.
- Power off controller B and restart it.
Check whether the indicator of controller B is steady green.
- If yes, go to 3.
- If no, keep the fault environment intact and contact technical support engineers.
- Switch services from controller A to controller B.
- Observe the service processing.
Enable the performance monitoring function before you check the service processing on the DeviceManager.
- Log in to DeviceManager and choose Insight > Performance > Analysis.
- Click Create.
The Create Chart page is displayed.
- Specify the value of Chart Name.
- Select LUN and Custom for Object Type. In Object Instance, select the LUN that provides services for the server through controller B.
- Select Total IOPS (IO/s) for Statistical Metric.
- Click OK.
Observe the I/O performance monitoring data and check whether the performance line is smooth.
- If yes, the service processing is normal and the procedure is complete.
- If no, keep the fault environment intact and contact technical support engineers.
Suggestion and Summary
To rectify the fault completely:
- Install UltraPath on the application server.
- Replace the faulty controller.
- Upgrade the storage system.
- Send the collected logs to technical support engineers for subsequent handling.
