[CentOS] SOLVED - Shutdown/poweroff does not power off machine

Eero Volotinen wrote:
> On 1/4/10 10:57 PM, Scot P. Floess wrote:
>> I've got a Dell Optiplex GX240 I am running CentOS 5.4
>> (kernel 2.6.18-164.9.1.el5.centos.plus)...  When I had Fedora 11 and 12 on
>> it, I could issue a poweroff command and the machine would power itself off.
>> However, under CentOS it doesn't turn the machine off whatsoever.  When it
>> completes, the machine is still running with a message of "system halted."
>> Then I have to physically hit the power button to turn it off...  I
>> believe at some point I did try to issue a shutdown command - but had the
>> same results...
>>
>> Anyone have any recommendations or suggestions?
> 
> buggy acpi support on server? Try updating to latest bios?

No, I'm not the OP. But, I found a solution for my system.

During boot, I noticed an error line --
"BIOS fails cutoff age - ACPI might not work. Use acpi=force to fix."

So I did; the machine now actually turns off after shutdown.