Chapter 5. Using the Online and Standalone Diagnostics
The diagnostics consist of online diagnostics and standalone diagnostics.
Attention: The AIX operating system must be installed in a partition in order to run
online diagnostics on that partition. If the AIX operating system is not installed, use the
standalone diagnostic procedures.
Online diagnostics, when they are installed, reside with AIX in the file system. They can
be booted:
vIn single user mode (referred to as

service mode

)
vTorun in maintenance mode (referred to as

maintenance mode

)
vTorun concurrently with other applications (referred to as

concurrent mode

)
Standalone diagnostics must be booted before they can be run. If booted, the
diagnostics have no access to the AIX error log or the AIX configuration data.

Online and Standalone Diagnostics Operating Considerations

Note: When possible, run online diagnostics in service mode. Online diagnostics
perform additional functions compared to standalone diagnostics. Running online
diagnostics in service mode ensures that the error state of the system that has
been captured in NVRAM is available for your use in analyzing the problem. The
AIX error log and certain SMIT functions are only available when diagnostics are
run from the disk drive.
Consider the following items before using the diagnostics:
vStandalone diagnostics can run on systems configured for either a full (or single)
system partition or a multiple partitioned system. When running in a partitioned
system, the device from which you are booting standalone diagnostics must be made
available to the partition dedicated to running standalone diagnostics. This may
require moving the device from the partition that currently contains the boot device
(for example, the CD-ROM or network adapter connected to the NIM server that has
a standalone diagnostic image) to the partition used to run standalone diagnostics. If
you move devices, reboot both partitions. For more information, see “Standalone
Diagnostic Operation” on page 88.
vWhen diagnostics are installed, the device support for some devices might not get
installed. If this is the case, that device does not display in the diagnostic test list
when running disk-based diagnostics.
vWhen running diagnostics in a partitioned system, diagnostics will work only with the
resources that were assigned to that partition. You must run diagnostics in the
partition containing the resource that you want to test.
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