Owner`s manual

If self-test fails after power-up or a system reset, the system may be hung
so that you cannot get a console prompt. The system hangs during the boot
process for one of two reasons:
• No boot processor can be found. Processors either are disabled from
becoming the boot processor or they fail self-test.
• No memory can be located.
Example 6–1 shows a case where no boot processor could be found.
Although there are three processors, two of the processors (at nodes 2
and 3) were made ineligible to become the boot processor (with the SET
CPU command and qualifiers). The third processor at node 1 is eligible to
be a boot processor, but it failed self-test. The system cannot find a boot
processor and hangs.
If the system hangs, after 60 seconds you can use the console program
to intervene. You can force a processor to become the boot processor and
override any previous commands by typing:
>>n
where n is the XMI node number of a processor. The console program then
makes this the boot processor. Self-test begins and processor n displays the
results of self-test. In Example 6–1 the processor at node 3 was forced to
become the boot processor. The >>n sequence is not echoed; you may have
to type this more than once to get to the console prompt.
Now you can examine the status of the processors by using the SHOW
CPU command. Self-test results do not give a true picture of the processor
status (BPD line), because you forced one of the processors to become the
boot processor. Only the SHOW CPU command gives the setting in the
EEPROM.
In Example 6–1, a next console action might be to SET CPU /PRIMARY
for the processors at nodes 2 and 3 to avoid repeating a processor lock. Not
all console commands are available to the system when you force a boot
processor, so it is useful to correct the cause of the system hang.
When a system hang is caused by inability to locate sufficient memory, the
processors cannot find memory as they attempt to run the extended test.
Partial self-test results are displayed and the following message:
?0047 Insufficient working memory for normal operation.
The system hangs here until the >>n command is entered. When a system
hang is caused by a memory problem and you force a boot processor, self-
test results show that either all memory failed self-test or that no good
memory exists. Check the installation of your memories and restart the
system.
System Self-Test and Troubleshooting 6–21