Re: Switching Kernels without Rebooting?

Jesse Pollard
2001-07-12T12:54:32Z

--------- Received message begins Here ---------

>
> >
> > On Wed, 11 Jul 2001, C. Slater wrote:
> > >Would anyone else like to point out some other task somewhat related
> > >and have me do it? :-)
> > >
> > >> > Before you even try switching kernels, first implement a process
> > >> > checkpoint/restart. The process must be resumed after a boot
> > >> > using the same
> > >> > kernel, with all I/O resumed. Now get it accepted into the kernel.
> > >>
> > >> Hear, hear! That would be a useful feature, maybe not network servers,
> > >> but for pure number crunching apps it would save people having to write
> > >> all the state saving and recovery that is needed now for long term
> > >> computations.
> > >
> > >Get a computer with hibernation support. That's just about what it is.
> >
> > Bzzzt wrong anser. Hibernation stops the entire kernel. checkpoint restart
> > stops processes, saves the entire state of the process. hibernation
> > is just halt the processor.
>
> Hibernation may not be.
> I've just suspended to disk after the list line, pulled the power supplies,
> taken the RAM chip out, shorted the pins to make really sure, then powered
> back up.
> Everything just resumed fine.
>
> All I'd need to do kernel migration is a quick vi of the
> disk file.
>
> (well, almost)

That sounds more like a memory dump to disk, and reload after power restored.
Either that or possibly a separate power supply for RAM (something like a
trickle discharge capacitor; I've read that some capacitors can hold a charge
for about 3 days. Whether that would work for a large RAM or not, I have no
idea).

-------------------------------------------------------------------------
Jesse I Pollard, II
Email: pollard@navo.hpc.mil

Any opinions expressed are solely my own.