Multiple Boot from PXE Scenario

[R P Herrold]

On Thu, 29 May 2008, Jason Spatafore wrote:

Sorry about the delay -- I've been travelling, just returned, 
and am ploughing through the email compost heap ...

> 1. I would like to use a system where servers can be 
> PXEBooted to the network.

doable for any reasonable hardware, thanks in part the Intel 
Wired for Management - initatives back in 1998 and 1999 - see:
    http://www.owlriver.com/tips/pxe-install/
and of course H Peter Arvin's Syslinux efforts.

> 2. The system needs to be able to boot from image files 
> after being PXEBooted. For example, image files can/will be 
> .iso (CD-ROM), .usb (USB Drive Images created with dd), .img 
> for floppy images, and .dvd for DVD based images.

Not sure I would use 'dd', but doable.  See Method C at:
    http://www.owlriver.com/tips/hands-off/
but rather than upgrading a local HD image, chain-boot into 
the next (post selection time) operation system setup.  We use 
that initial image to collect the desired profile, and to 
'prime the pump' to use the MAC address "NEXT" PXE reboot

> Here's how I see the system working. A technician boots to 
> the PXE environment and is presented a menu...say the menu 
> is asking for an 8 digit number. The technician inputs the 8 
> digit number (12345678) and a script of some kind locates 
> the corresponding image file.

Once I had posted the desired profile, I would THEM use the 
MAC address.  I do something like this to emit 'custom' 
kickstart configurations on the fly.  See:
    http://www.owlriver.com/tips/tiny-centos/

The script then determines the 
> type of image that is used based off the extension. In this 
> example, let's say the filename is 12345678.iso. The script 
> now knows that it must use iso9660 for the filesystem. The 
> script then loads that iso file and the system boots just 
> like it was running from a CD-ROM.

The 'smarts' can live on the back end in the PXE/Next server 
side and be of arbitrary complexity.  Databases, LDAP, and all 
the modern tools to tie into a LAMP server are MUCH easier to 
develop, debug, and handle on the server side than at the 
clients.

> Now, everything I have read so far states that this is 
> impossible due to the way systems boot.

ummm ... no.  Been there, done that, have the Tee-shirt.

> Does anybody have ideas on how to get something like this to 
> work? Can you boot an ISO file *as if* it was a direct 
> attached CD-ROM drive? Can you do the same with other image 
> types?

Yup -- done in xen instances all the time; before that, fond 
in LTSP applications -- no reason one cannot have a standard 
(and thin) Xen Dom0, and any DomU you wish -- Linux, Windows, 
whatever.

good luck -- very doable.

-- Russ herrold