None of the commands that would lead to a reboot are successful (e.g., reboot, shutdown -r now, init 6, etc.) The machine hangs after issuing "rebooting system." The keyboard lights flash as if the box were going to bounce but it just never follows through. Could APIC/ACPI have anything to do with it (see below)?

Any help is greatly appreciated!

[root@duffalo ~]# dmesg | grep APIC
ACPI: MADT (v001 A M I OEMAPIC 0x12000520 MSFT 0x00000097) @ 0x1dfc0390
ACPI: Local APIC address 0xfee00000
ACPI: LAPIC (acpi_id[0x01] lapic_id[0x00] enabled)
Processor #0 15:4 APIC version 20
ACPI: LAPIC (acpi_id[0x02] lapic_id[0x81] disabled)
ACPI: IOAPIC (id[0x01] address[0xfec00000] gsi_base[0])
IOAPIC[0]: apic_id 1, version 17, address 0xfec00000, GSI 0-23
Enabling APIC mode: Flat. Using 1 I/O APICs
mapped APIC to ffffd000 (fee00000)
mapped IOAPIC to ffffc000 (fec00000)
ENABLING IO-APIC IRQs
ACPI: Using IOAPIC for interrupt routing
APIC error on CPU0: 00(40)

My guess is you have answered your own question. Try the parm at boot time (you can pass it to grub).

If that works and you want to make the change permanent, you can add the parm to /boot/grub/grub.conf on the kernel line.

I've already tried that one with no success. Does the APIC service/daemon have anything to do with this? (I guess it is pretty apparent I have essentially no idea what APIC/ACPI is. Can anyone enlighten me?)

Haven't seen a problem like that since back in the 2.6.12/13 timeframe.
What kernel level are you ???.

Everything on the box is up to date: Kernel = 2.6.16-1.2133_FC5

Also try the kernel parameter (in addition to the first one).

I really appreciate all of the suggestions. All of my efforts have been in vain, though. I would really like to learn something from this experience anyway: what is APIC/ACIP? Why might one or the other cause this problem? Why might one imagine that disabling one or the other would help?

I am having the same problem, although my servers are FC3. The only way I can reboot is by connecting a PS/2 keyboard to the servers. Does any one has additional suggestions on how to troubleshoot this issue?

Thanks,

David

Added to boot parameters: reboot=bios.