Re: Process Migration on Linux - Impossible?

Victor Yodaiken (yodaiken@chelm.cs.nmt.edu)
Wed, 1 Oct 1997 16:11:33 -0600

On Wed, Oct 01, 1997 at 11:05:01AM -0500, Tall cool one wrote:
> Victor Yodaiken <yodaiken@chelm.cs.nmt.edu> writes:
> > On Tue, Sep 30, 1997 at 10:06:25PM -0500, Tall cool one wrote:
> > > Personally, I don't have a real need for process migration, but I'd like
> > > to see it because of what process migration would allow. The ability of
> >
> > So you want fault tolerance, not process migration. Don't confuse the
> > technique with the result.
>
> That's an odd thing to say, isn't it? Re-read my first sentence again,
> carefully this time. If one can throw a process on another machine at will,
> it becomes trivial to checkpoint, yes? Fault tolerance for free.

No. And in any case, its almost always a mistake to argue that Y is
desirable, X makes Y possible, so X is desirable. Having
process migration leaves you a long way from having fault tolerance.
More importantly, if I wanted to add fault-tolerance to Linux I would
certainly not start by implementing process migration.

> I'm the first to admit, that the above things are not really that
> important to me, just neat and potentially useful. The process migration
> thread just made me think about them and suggest potential other (simular)
> uses for it.

I think fault tolerance is a wonderful thing. But process migration seems
to me to be like virtual memory file systems, a clever idea with no
clear applications.

---------------------------------
Victor Yodaiken
Department of Computer Science
New Mexico Institute of Mining and Technology
Socorro NM 87801
Homepage http://www.cs.nmt.edu/~yodaiken
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