On Jul 26, 2006, at 11:35 AM, Tom Brown wrote:

I could be going mad but it there a way to force a PXE boot on next reboot? ie tell the box that next time it reboots try a PXE boot first?

that depends on the BIOS of your system; it's not an issue that CentOS can (easily) deal with. some Dell servers have a utility that you can use to change BIOS settings from within the OS, but i can't speak to how well it works.

here's how i solved a related problem when setting up a lab of machines that would be PXE-booting to reinstall themselves without an admin at the console:

1) in the BIOS, set the boot order to PXE,HD (you can put CD/floppy/ USB before HD if you want, but PXE must be first) 2) set up your TFTP server such that the default boot target boots from the system's hard drive (use the "LOCALBOOT" option as described here: http://syslinux.zytor.com/faq.php) 3) created another PXELINUX configuration that performs a network boot and give it a name that corresponds to either the machine's MAC address or the machine's IP address (as described here: http:// syslinux.zytor.com/pxe.php#config) 4) if you're using the PXE boot to kickstart the machine, add a line to the %post section of your ks.cfg that will ssh to the TFTP server and move aside the PXELINUX config file with the machine's MAC/IP address (you can make this process as simple or complicated as you need)

if you follow these steps, then the machine will PXE-boot when the special config file is in place, kickstart itself, and then move the special config file aside; when it next boots, the TFTP server won't find the special config file, so it'll use the default config file, which tells the machine to boot from the local hard drive.

does this make sense?

-steve

p.s. there are other ways of having the machine "phone home" to the tftp server besides using ssh; one of my colleagues did it with a little php script. alternately, you could have a script running on the TFTP server that watches the logfile for evidence of successful PXE boots and uses that information to move aside the special config file.

--- If this were played upon a stage now, I could condemn it as an improbable fiction. - Fabian, Twelfth Night, III,v

On Wed, 2006-07-26 at 16:35 +0100, Tom Brown wrote:

Hi

I could be going mad but it there a way to force a PXE boot on next reboot? ie tell the box that next time it reboots try a PXE boot first?

thanks

I don't know Dell machines very good (i'm more familiar with IBM Machines ....) but for IBM machines in the Bios you have two boot sequence listed : - the normal one (that you can still force to use pxe first if you want to ...) - the wake-on-lan boot sequence one : this order is applied only when the machine is booted remotely through a wake-on-lan packet

Look at the Dell bios to see if such thing exists for your Dell servers. To send a wake-on-lan packet from another machine you can use wol (available in the rpmforge repo)