[vox-tech] need to debug boot crash

[ME]

[chopping previous parts]

On Tue, 26 Mar 2002, eric nelson wrote:
> First, our bios mentions something about netboot.  This must be something
> pretty generic, that works w/ various OS's.  So, doing a netboot from the
> bios, is this the same type of thing?

It depends. I have encountered 4 different BIOS based netboot
options. Each of the 4 I encountered were different. Three of which were
closed proprietary systems that were not published - claiming you had to
buy a specific vendor's netbooting server software (Each of the three had
a different vendor). This was during the time period 3-4 years ago when
"thin client technology" and "distributed desktop computing" were big
marketing-phrases along with "total cost of ownership."

(An IBM ThinkPad 560, a Dell OptiPlex Gn+ (old), an IBM Desktop machine
(dont recall model) and a "no name" PC used by someone I was helping. (I
saw the netboot option in their BIOS and complained they seemed to be
closed an proprietary and useless for most people, and he said that he
thought his was more open and his MoBo manual actually described the boot
process (more open.)

I never examined these netbooting schemes in BIOS very closely, but would
guess they were similar to previously mentioned booting processes for
*NIX systems.

On the 4th system (a more recent system) the net booting procedure was
published and seemed to match the whole:
dhcp request, dhcp response includes loction of image from tftp, tftp
image, boot image, mount root filesystems, go with startup.

Newer Dell machines have this option as well, and I have been meaning to
try it. If they published this process I could easily test it. If it is
not published, I could probably make something work and publish it for
them ]:> but dont have much free time. Maybe if I am at home some time, I
set up a private network, and some net booting services to test it out.

So, the short answer is:
"It depends on your vendor and if they have published their netbooting
processes supported from their BIOS."

> Last, for now, what we really want to do is read a switch from a port,
> then either do a normal boot, off the flash disk, or boot into some
> menu which will allow either booting into a diagnostic shell which
> will permit adding new software, running diagnostics etc., or doing
> the netboot we have been talking about, I guess this is all possible
> using all this stuff, along w/ lilo, and some shell scripts, etc.  (I
> am just asking for affirmation, this is our plan).

If the BIOS supports the "standard" *NIX net booting

bootp/dhcp request, bootp/dhcp response with location to tftp kernel and
nfsroot++, tftp download the netbootable-modified-kernel and execute it,
boot kernel, and mount root, then start init

Yep, it should be pretty easy.

Of course, you know, netbooting should not really be done over anything
less than 10Mbps. I have locally netbooted but used an NFS root from an
ISDN speed link (128kbps) and it is painful. Root over T1 (1.544Mbps) is
almost bearable, while Ethernet (~10Mbps, usually about 60-80%) is not too
bad at all - even with lots of clients. Over a swicthed network even
nicer. If this product is meant for use with remote offices over slow
links, you may have some problems with speed.

-ME

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