[Beowulf] BIOS

[Jeff Johnson]

Bios updates on large clusters, wonderful way to spend a weekend...

It is possible to use PXE to do bios updates and setting nvram. Success
depends in part on your platform/motherboard manufacturer. Some of the
manufacturers have a DOS utility that will dump the bios settings to a
.bin file and the same utility can flash the .bin file to the
motherboard as a single step, non-interactive and scriptable
(autoexec.bat) process. If you have these utilities, a functional
FreeDOS PXE image, remote power control over your cluster (IPMI or ip
based PDUs) and serial console servers for your nodes it all works. I
have updated 250 node clusters from across the country via an ssh tunnel
in this way.

The best way I have found is to update the bios on one node. Manually
clear and reconfigure bios settings for your requirements. Dump the
nvram using the DOS nvram utility provided by the motherboard vendor.
Then add the utility and .bin file to a PXE FreeDOS image and set the
script to flash the bios then flash the nvram. Done right, it works like
a charm. (caveat: you must pay *very close* attention to your configs,
scripts, settings, etc before unleashing an automated process like this
on an entire cluster).

There are things that can be done within the Linux environment to tweak
machine settings. Manually editing PCI registers and dumping /dev/nvram.
Personally I would not rely on those methods. Manufacturers of
processors and motherboards are putting a fair amount of "windage" in
the BIOS and hidden, non editable BIOS registers these days. Hiding
flaws, fixing errata, etc. If you use a bios editor from AMI, for
example, you can see much more going on than the settings you are
presented with.

Only thing worse than manually updating a bios in a cluster is bricking
an entire cluster doing it the wrong way.

--Jeff


beowulf-request at beowulf.org wrote:
> how does it fail?  I'm guessing the issue is that there are LOTS more 
> settings now than with the PC-AT (hypertransport frequency, etc).
> it would be most interesting to know where those are stored - perhaps 
> even in the same flash as the bios itself?

-- 
Best Regards,

Jeff Johnson
Vice President
Engineering/Technology
Western Scientific, Inc
jeff.johnson at wsm.com
http://www.wsm.com

5444 Napa Street - San Diego, CA 92110
Tel 800.443.6699  +001.619.220.6580
Fax +001.619.220.6590

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