Re: Just an offer

Richard B. Johnson (root@chaos.analogic.com)
Fri, 17 May 2002 10:48:21 -0400 (EDT)


On Fri, 17 May 2002, Tomas Szepe wrote:

> > The remaining problem is how one trips a reboot if the remote machine
> > doesn't come up correctly. That problem can be handled by temporarily
> > changing panic() to a hard reset.
>
> Trouble is, this couldn't "detect" problems like unresolved symbols in
> ethernet drivers or a troublesome fix that makes init/mount malfunction
> and many more common issues that make you have to get in the car and
> drive off to reset the damn beast.

Where there is a will, there is a way. As others have reported, you
can have an old "always-on" machine at the remote site. You can have
LILO redirect kernel messages out the serial port to be viewed
from your always-on machine, you can reset the hung machine with an
opto-isolator driven off your always-on machine's parallel port, etc.

It you are really serious about doing remote updates, you can also
boot using initrd, and install a bunch of disk drivers until one
(or more) don't fail to install, install a bunch of ethernet drivers
until one (or more) don't fail to install, etc. This can all be
handled in the initrd boot-script. --And that boot-script can be
a full-fledged 'C' program that can do anything a root-priviliged
program can do, including mounting an alternate root file-system
(maybe a CDROM) if all else fails. You don't have to use the default
"run-off-the-end-of-the-script" initrd process. Any program that
you write to replace the ash.static/initrd script has complete
control of the machine.

Booting an initial RAM-Disk requires NO hardware drivers! The
thing got loaded by LILO, through the BIOS services, then a
transition to protected-mode, you don't need anything installed.
Your program or script can try all possible drivers, trying to
get a root file-system on-line. The same for a network card.

Anyway, once it boots and you can review what actually got installed
from the network, you can make a final initrd boot-script.

Cheers,
Dick Johnson

Penguin : Linux version 2.4.18 on an i686 machine (797.90 BogoMips).

Windows-2000/Professional isn't.

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