[ipxe-devel] HTTP SAN / ISO booting

[Andrew Bobulsky]

Most likely you're running into what is essentially a "Missing boot
device driver."  Commonly a "7B" blue screen on Windows.

While iPXE can speak HTTP just fine and translate an ISO file as a
physical disk to BIOS, because HTTP-sourced SAN devices don't have a
BFT mechanism like iSCSI does (the iBFT), iPXE can't pass information
about what the "boot" device is or how to access it to the operating
system once it's online.  Presumably, after the CentOS live CD you're
using loads the kernel and its drivers, it still needs to source more
files from that CD to finish the boot process.  iPXE is non-functional
at that point, and since the OS can't find the disk, it crashes.

Any Live CD that boots *completely* into a RAM disk will work very,
very well with this boot method though.  I use it to boot Windows PE
3, and on a moderately fast computer, it's online in 10 seconds or so.

Perhaps someone else on the list could suggest a Live CD for CentOS
that boots from a RAM disk device?

Best Regards,
Andrew Bobulsky



On Fri, Jul 29, 2011 at 1:32 PM, James A. Peltier <jpeltier at sfu.ca> wrote:
> ----- Original Message -----
> | Hello,
> |
> | James, Michael merged his ISO SAN boot code into the mainline (master
> | branch?) iPXE just a few days after the commit referenced in that
> | original email. I'm not sure if that fact made the mailing list or
> | not... I think he mentioned it on IRC when I heard it.
>
> Ahh yes, I see that now.  Don't know how I missed it!
>
> Okay, so I tried it using a CentOS 6 Live CD ISO image and while it boots a KVM host fine if I use the raw image, when I use sanboot path to image, it boots to a certain point and then dies with an error and I'm not sure if this is an iPXE issue or a scripting issue.  Booting FreeDOS as Michael described does work.  Here is the error from the CentOS Live CD
>
> No boot device found
> Boot has failed, sleeping forever
>
>
> Below is my iPXE script
>
> #!ipxe
> echo "Hi There!  We will be booting from http://mirror.its.sfu.ca/ today."
> echo "It is assumed that you have dhcp networking available."
> :retry
> dhcp || goto retry
> set 210:string http://mirror.its.sfu.ca/mirror/CentOS/6/isos/x86_64
> echo "Here we go!"
> sanboot ${210:string}/CentOS-6.0-x86_64-LiveCD.iso || goto retry
>
> --
> James A. Peltier
> IT Services - Research Computing Group
> Simon Fraser University - Burnaby Campus
> Phone   : 778-782-6573
> Fax     : 778-782-3045
> E-Mail  : jpeltier at sfu.ca
> Website : http://www.sfu.ca/itservices
>          http://blogs.sfu.ca/people/jpeltier
>
>
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