[Beowulf] reboot without passing through BIOS? (UNCLASSIFIED)

Henry, Kevin A CTR USA ATEC kevin.a.henry at us.army.mil
Wed Jul 30 12:11:26 PDT 2008

Classification:  UNCLASSIFIED 
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>From the grub prompt one can do the following

savedefault --default=3 --once 

I don't know if there is a command-line equivilent. 

Henry, Kevin A
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Email: kevin.a.henry at us.army.mil
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-----Original Message-----
From: beowulf-bounces at beowulf.org [mailto:beowulf-bounces at beowulf.org]
On Behalf Of David Mathog
Sent: Wednesday, July 30, 2008 2:07 PM
To: Lombard, David N
Cc: beowulf at beowulf.org
Subject: Re: [Beowulf] reboot without passing through BIOS?

David Lombard wrote:

> On Wed, Jul 30, 2008 at 09:13:56AM -0700, David Mathog wrote:
> > It then occurred to me that doing so would
> > require a trip through the BIOS on every reboot, at least on every
> > based computer I'm familiar with.
> Not since kexec was added to the kernel!

That's exactly what I was thinking of for the Beowulf node problem.
For instance:


> Beyond using kexec as described above, grub directly supports this;
> did too.

I know how to do this by changing the configurations, but not how to
specify a one time change that doesn't need to be manually undone later.
Is either of these boot loaders capable of doing the logical equivalent

  grub-next-boot-only -default 3

(Override whatever default is in the config file, but just for the next


David Mathog
mathog at caltech.edu
Manager, Sequence Analysis Facility, Biology Division, Caltech
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Classification:  UNCLASSIFIED 
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