Non-SMP on SMP hardware

[Hendrik Strydom]

On Mon, 2006-08-28 at 17:39 -0600, Ashley M. Kirchner wrote:
>     I just finished installing FC5 on a machine and now I can't boot it 
> up.  The motherboard supports two CPUs, however only one's installed.  
> But for some stupid reason, the installer decided to put only the smp 
> kernel on, instead of both the smp as well as the single (one-up) 
> kernel, so I can't boot the machine now.  It locks up during the boot 
> process, doing what appears to be something with CPU1 which doesn't 
> exist.  It goes through CPU0 just fine then quits.  Does anyone have any 
> suggestions on how to rectify this problem now?  The machine does not 
> have a CD drive in it so I can't boot the rescue (or any other) disk.
You may have success by adding
isolcpus=1
to the kernel command line, which should limit your system to using
CPU#0.
Alternatively you could boot from floppy, chroot to the installed root
and manually add a non-smp kernel from the NFS mounted source with rpm
-i.

>     With past FC versions it always installed two kernels, one smp and 
> one non-smp so I always had the choice to boot with the single one (then 
> proceed to remove the smp one since I don't need it.)  Apparently FC5 
> disagrees with that arrangement.
It was recently reported on the list that FC6 will only ship with SMP
kernels, since it works fine on (most) uni-processor units.

Regards
   Hendrik

>     For those curious, I booted it through floppies [1] and did an NFS 
> install.
> 
>     [1] http://www.thisiscool.com/fcfloppy.htm
> 
> -- 
> W | It's not a bug - it's an undocumented feature.
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