Performing Basic Steps - Lenovo ThinkSystem DS Series Hardware Installation And Maintenance Manual

Performing basic steps

You can use any of the available options described above in performing the basic steps comprising the fault
isolation methodology.
Gather fault information
When a fault occurs, it is important to gather as much information as possible. Doing so will help you determine
the correct action needed to remedy the fault.
Begin by reviewing the reported fault:
•
Is the fault related to an internal data path or an external data path?
• Is the fault related to a hardware component such as a disk drive module, controller module, or power supply
unit?
By isolating the fault to one of the components within the storage system, you will be able to determine the
necessary corrective action more quickly.
Determine where the fault is occurring
When a fault occurs, the Module Fault LED—located on the Ops panel on an enclosure's left ear illuminates.
Check the LEDs on the back of the enclosure to narrow the fault to a CRU, connection, or both. The LEDs also
help you identify the location of a CRU reporting a fault. See also
enclosure rear panel" (page
Use the SMC to verify any faults found while viewing the LEDs. The SMC is also a good tool to use in determining
where the fault is occurring if the LEDs cannot be viewed due to the location of the system. This web-application
provides you with a visual representation of the system and where the fault is occurring. The SMC also provides
more detailed information about CRUs, data, and faults.
Review the event logs
The event logs record all system events. Each event has a numeric code that identifies the type of event that
occurred, and has one of the following severities:
• Critical. A failure occurred that may cause a controller to shut down. Correct the problem immediately.
•
Error. A failure occurred that may affect data integrity or system stability. Correct the problem as soon as
possible.
• Warning. A problem occurred that may affect system stability, but not data integrity. Evaluate the problem and
correct it if necessary.
• Informational. A configuration or state change occurred, or a problem occurred that the system corrected. No
immediate action is required.
NOTE: Some events also have a Resolved severity that indicates that a previously logged non-Informational
condition has been resolved. See the Event Descriptions Reference Guide for information about specific events.
The event logs record all system events. It is very important to review the logs, not only to identify the fault, but
also to search for events that might have caused the fault to occur. For example, a host could lose connectivity to a
disk group if a user changes channel settings without taking the storage resources assigned to it into consideration.
In addition, the type of fault can help you isolate the problem to either hardware or software.
Isolate the fault
Occasionally, it might become necessary to isolate a fault. This is particularly true with data paths, due to the
number of components comprising the data path. For example, if a host-side data error occurs, it could be caused
by any of the components in the data path: controller module, cable, or data host.
108 Troubleshooting and problem solving
34).
"2U enclosure rear panel" (page 27) and "5U