IBM RS/6000 - Manual (Page 171)

Chapter 8. Diagnostics Support
One of the most important features provided by the PCI-based RS/6000 servers is
support of the AIX diagnostics programs. Servers, by their nature, should provide
enhanced Reliability, Availability and Serviceability (RAS) features. Access to AIX
diagnostics, stand-alone and online, helps provide these features (which are
available on the microchannel-based RS/6000 systems). Both the 40P and 43P
PCI-based RS/6000 workstations do not provide support for AIX diagnostics.
Instead, limited diagnostics is provided from the System Management Services.
The programs provided, however, are not as powerful as the AIX diagnostics. In
addition, these diagnostics cannot be run concurrently with the AIX operating
system. To run diagnostics from System Management Services, the system has to
be rebooted.
In addition to providing diagnostics support for new PCI and ISA devices available
for the PCI-based RS/6000 servers, a major change had to be made to the
firmware. On microchannel-based RS/6000 systems, diagnostics can be loaded by
switching the physical key to the service position and booting the system. If using
online diagnostics, AIX will determine that the key is in the Service position and
boot diagnostics. Support for booting diagnostics from CD-ROM is also provided.
PCI-based RS/6000 servers do not have a physical key; so an extra function had to
be added to the firmware to allow a logical representation of the keyswitch which
would allow the system to either boot in "Normal" or "Service" mode. Both the E20
and F30 have this "electronic keyswitch" function (see 5.1, “Electronic Key-Switch
Function” on page 75), and the system can either be booted in Normal or Service
mode by pressing a function key during the firmware POST stage. Additionally,
support had to be added to enable the system to load diagnostics from CD-ROM.
Two methods of running diagnostics are supported on the PCI-based RS/6000
servers:
Stand-alone Diagnostics
Online Diagnostics
Both of these methods are described in this chapter.
8.1 Diagnostics Operating Considerations
The following items identify some issues to consider before using the diagnostics
programs.
Device Diagnostics
If diagnostics support is not installed on your system and you install this option,
device support for devices physically installed in your machine will not be
installed. Diagnostics support is, however, automatically installed when you
install from an AIX Version 4.1.4 server CD-ROM. The Online Diagnostics test
list will display entries for all the devices in your system which have diagnostics
support.
Selecting a Console Display
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