Ken Teh wrote:
> cpuspeed was off.  If I say 'shutdown -h now', the machines powers off 
> after a clean shutdown.  If I say 'shutdown -r now', it brings the 
> machine down.  The last steps are remounting md0 readonly and syncing 
> the SATA drives.  The last line it prints on the screen is 'Restarting 
> system'.  Then, it just sits there.  I have to use the front-panel 
> switch to turn it off, then power it back on.  Which is a bummer if 
> you have to reboot it remotely. Btw, the front-panel switch is one of 
> these new types when you have to hold it down for several seconds 
> before it actually powers the machine off.
>
> I'm wondering if it's some hardware problem.  It's my understanding 
> that a restart is basically like a push button reset.  The last thing 
> the CPU does is pull the reset line (A20 or A21 ??) which causes the 
> M/B to go through its boot-up.  But, now with ACPI and these smart 
> power supplies, I was wondering if somehow this is the cause of my 
> problem.
I am sorry, cpuspeed was my one suggestion. But in the problem we had, 
and on our motherboards, a pushbutton reset did NOT seem to be exactly 
the same as a warm reboot. It seems like the pushbutton reset cleared 
more state than the warm reboot. cpuspeed caused us to hang up much 
later in the boot, when the daemons (including cpuspeed) were starting. 
If we then pressed reset, the reboot was successful. So we ended up with 
a worked-once/failed-once kind of toggling.

You might try turning off any ACPI stuff in the BIOS. But I am grasping 
at straws.