[syslinux] Multiple PXE server Issue

[Gene Cumm]

On Tue, Feb 17, 2009 at 1:31 PM, Jeffrey Hutzelman <jhutz at cmu.edu> wrote:
> --On Tuesday, February 17, 2009 05:06:42 PM +0000 John Rouillard
> <rouilj at renesys.com> wrote:
>
>> On Fri, Feb 13, 2009 at 12:19:32PM -0700, FoM - Technology Services wrote:
>>> And here's the problem.... Ghost is using a PXE server so that the
>>> computers can be booted off the network and easily re-imaged. Citrix
>>> provisioning server requires the use of a PXE server so that the
>>> thick\thin clients can boot off the network directly to the server. But
>>> it's standard that the first PXE server to answer is what the computer
>>> gets.
>>>
>>> How can we make (2) PXE servers work in the same network?
>>>
>>> I understand that you could separate out the subnets, so that (1) PXE
>>> server only answers in that sub-net. But that's only a temporary fix.
>>> Once we have Citrix working, then other labs within the schools network
>>> may slowly switch over to Citrix as well. And both Ghost and Citrix PXE
>>> servers will need to co-habitat.
>>>
>>> Is there a way that I could set up an PXELinux box so that it's
>>> essentially a "PXE Re-Director".  For example a user boots up their PC
>>> via Network.  It will then go to the PXELinux server (as pre-setup via
>>> the network somehow) and the user is given an option; (a) Citrix or (b)
>>> Ghost.  By choosing one of these items you will then be taken to that
>>> particular PXE server of your choice and continue on from there.
>>
>> IIRC in dhcp you can specify the next boot node. But this requires
>> recording the ethernet address of any hosts you want to boot.

In my organization, this is about how I was able to have all of the
PCs reconfigured to use PXE boot (LoM: LAN on Motherboard) but not
take 15-30 seconds for it to slowly fail out.  In the DHCP server, I
set the next server and filename but I set it to one boot server for
all of our subnets (until I get a better PXE system running for
imaging purposes).  For most subnets, I have a very controlled and
simple PXELINUX configuration file but for more system administrative
networks, I opened more control and options (2 text files, over 100
symlinks).

This kind of a setup is more of a DHCP directed network boot than PXE.
 Going to the PXE Specification v2.1: "The PXE boot ROM must function
as a normal DHCP boot ROM in the absence of a PXE specific response."

Which ever direction you choose to solve this, it appears that you'll
need either the assistance of the DHCP administrator(s) or to control
DHCP yourself (even if you went to a DHCP server that handles PXE
extensions, an even more elaborate setup).  This is the only way to
make the situation predictable and be able to choose your boot.

> You could also give all hosts PXELINUX and a menu that lets the user select
> between ghost, citrix, and whatever else, using pxechain.cbt to chain to
> the next boot server.  See previous discussion on this mailing list and
> PXECHAIN.ASM in recent Syslinux distributions.

I'll have to investigate this module sometime.  Thanks.

-- 
-Gene

"No one ever says, 'I can't read that ASCII E-mail you sent me.'"