Repeated PXE jumpstart

[Erik Cederstrand]

Found the answer elsewhere, so this is just for the records...

Erik Cederstrand wrote:
> Hi!
> 
> I'm trying to set up a system to continually and automatically run 
> benchmarks on the most recent CURRENT. The idea is to PXE-boot the 
> server, do an automated jumpstart installation, reboot and run a few 
> benchmarks. Lather, rinse, repeat.
> 
> My problem is when the jumpstart installation finishes. I set PXE-boot 
> as the first option in the BIOS to start the installation. To complete 
> the installation I need to reboot the server from the hard-disk, but I 
> don't want to enter the BIOS on each reboot to change the boot sequence.
> 
> What are my options? Can I simply set the hard-disk as the first option 
> in the boot sequence (with PXE second) and then wipe the MBR when the 
> system comes up after an install, so the BIOS will continue to PXE? How 
> would i do that?

# sysctl kern.geom.debugflags=16
# dd if=/dev/zero of=/dev/ad0 bs=512 count=1

wipes the MBR and solves my problem.

Erik