System may disable processor(s) during BOOT - IBM eServer xSeries 360

Resolving The Problem

Source

RETAIN tip H174623

Symptom

During system POST boot, the following symptoms occur:

• Processor (X), where (X= 1, 2, 3, or 4), is displayed on the system monitor as "not functioning".
• The system eventually hangs during boot if item (1) above happens until all processors installed have been disabled.
• The Fault LED indicates a CPU problem and indicates which processors have been taken off-line. This will be logged in the System Error Log (SEL).
• The operating system reports fewer processors than are physically installed.

Affected configurations

• The system may be any model of the IBM xSeries 360, type 8686 server.
• The system is configured with one or more (1-4) processors.
• The BIOS levels affected is 1.00.

Solution

• The behavior described above will be corrected in BIOS 1.01 release.
• The target date for the release is scheduled for December 10, 2001.
• It will be available from the following URL: http://www.ibm.com/systems/support

Workaround
If the problem occurs, remove and reapply AC power to the system to enable all processors.

Additional information

• During boot/reboot of the system, you may have one or more of the symptoms mentioned above.
• The boot processor will be taken off-line by system logic and the system will be rebooted without that processor in the configuration.
• When the last available processor is taken off-line because of subsequent POST errors, the system will hang during boot.
• Lightpath will indicate a CPU problem and indicate which processors have been taken off-line.
• All processors can be brought back online by removing and reapplying AC power to the system.
• BIOS 1.01 fixes the problem by setting initial bus timings to an optimal value early in the boot process.