When a disk drive LED lights steadily and is green, it indicates thatthe slot is
populated and that the drive is receiving power. When an LED is green and flashing,
it indicates that there is activity on the disk. Some applications use the LED to
indicate a fault on the disk drive. In this case, the LED changes color to yellow and
lights steadily.The disk drive LEDs retain their state when the system is
powered off. A yellow indicator also results in the yellow general fault indicator
being lit on the system front panel.

7.12.1.5 Error Messages

Error messages and other system messages are saved in the file/var/adm/
messages.
The two firmware-based diagnostic tools, POST and OBDiag, provide errormessages
either locally on the system console, or terminal, or in a remote console window
through a tip connection. These error messages can help to further refine your
problemdiagnosis. Theamount of error information displayed in diagnosticmessages
is determined by the value of the OpenBoot PROM variable diag-verbosity. See
Section 7.5.2 “Configuration Variable”on page 194 for additional details.
7.12.2 Software Commands
System software provides Solaris operating system commands that you can use to
diagnose problems, and OBP commands that enable you to diagnose problems even
if the Solaris operating environment is unavailable for any reason. For more
information on Solaris commands, see the appropriate man pages. For additional
information on OBP commands, see the OpenBoot 3.x Command Reference Manual.
(An online version of the manual is included with the Solaris System Administrator
AnswerBook that ships with Solaris software.)

7.12.2.1 Solaris prtdiag Command

The prtdiag command is a UNIX shell command used to display system
configuration and diagnostic information, such as:
System configuration, including information about clock frequencies, CPUs,
memory,and I/O card types
Diagnostic information
Failed field-replaceable units (FRUs)
Torun prtdiag, type:
%/usr/platform/sun4u/sbin/prtdiag
216 Sun Enterprise 220R Server Service Manual ♦January 2000, Revision A