Red Hat Knowledgebase

Release Found: Red Hat Enterprise Linux 3 x86_64/EM64T

Symptom: During the boot sequence the system hangs. The following message (or something similar) may be displayed on the screen:

testing NMI watchdog ... CPU#0: NMI appears to be stuck! Using local APIC timer interrupts. Detected 0.000 MHz APIC timer. cpu: 0, clock: 0, slice: 0

Solution: Check and see if Advanced Programmable Interrupt Controller (APIC) is disabled in the BIOS. If it is, re-enable it. In this particular issue, re-enabling APIC in the BIOS resolved the boot sequence hang.

If you have to disable APIC for whatever reason, do not do it via the system BIOS. Use a boot option to disable APIC. The best way to do this is to modify the /etc/grub.conf file to include "noapic", for example:

title Red Hat Enterprise Linux WS x86-64 (2.4.21-15.EL) root (hd0,0) kernel/vmlinux-2.4.21-15.ELroroot=LABEL=/ hdb=ide-scsi noapic initrd /initrd-2.4.21-15.EL.img

NOTE: The 32-bit version of Red Hat Enterprise Linux 3 will not exhibit this symptom.