Problem determination and recovery

AIX® diagnostics and utilities are used to assist in problem determination and recovery tasks.

Note: The procedures contained in this section are intended for service representatives specifically trained on the system unit and subsystem that is being serviced. Additionally, some of the service actions in this topic might require involvement of the system administrator.

If a problem arises related to disk arrays and associated pdisks, use the following to identify the problem:

Information presented by the error log analysis
Hardware error logs viewed using the Display Hardware Error Report diagnostic task
Disk array hdisk and pdisk status, viewed using the IBM® SAS Disk Array Manager

Error log analysis analyzes errors presented by the adapter, and recommends actions that need to be performed to correct the errors. It is sometimes recommended that you perform a maintenance analysis procedure (MAP) to further determine what actions should be taken to resolve the problem.

The MAPs contained in this topic are intended to address only problems directly related to disk arrays and SAS problem isolation. MAPs related to other device or adapter problems, when applicable, are located in other system documentation.

Read the following before using these problem determination and recovery procedures:

If a disk array is being used as a boot device and the system fails to boot because of a suspected disk-array problem, boot using the Standalone Diagnostic media. Error log analysis, AIX error logs, the IBM SAS Disk Array Manager, and other tools are available on the Standalone Diagnostics to help determine and resolve the problem with the disk array.
When invoking diagnostic routines for a controller, use the Problem Determination (PD) mode instead of System Verification (SV) mode unless there is a specific reason to use SV mode (for example, you were directed to run SV mode by a MAP).
After diagnostic routines for a controller are run in SV mode, run the diagnostics in PD mode to ensure that new errors are analyzed. Perform these actions especially when using Standalone Diagnostic media.