Re: Swap over network

Pavel Machek (
Tue, 29 Apr 1997 14:11:58 +0200

> > I've heard that there's some patch into kernel which makes swapping
> > over nfs to actually WORK.
> Do you got an URL to it?
> After hearing about some theoretical figures that said it would be a
> performance increase swapping to the net (compared with swapping to local
> disc) when you have a couple of boxes in a local net (even on 10MBit/s) I
> thought about implementing this (if possible due to the deadlock problems
> you mention) in two user-space processes, one to swap out data on the net

You can not have program which cares for swapping on client as user-level:
What if it gets swapped out?

> and one to store other machines swapped out memory (it will probably
> require some kernel-hacking, but I would try my hardest to keep
> stuff like that to a minimum).
> It probably hasn't much real-life application (I would never trust even a
> local net with parts of my core) right now, but as 100MBit/s networking
> become more and more popular it could be fun to experiment with.

It has. At home I have one machine (Elf) with 20M of ram, plan to
create second (hobit) with 8M of ram. Hobit will need to swap,
somehow - and swapping over 10mbit ethernet may be quite nice way.

> Anyone who has looked at the swapping part of the kernel and know if my
> idea is even doable?

It is. But it will be HARD. I'm trying to implement it... Probably, it
can not be done over TCP... WIll have to use UDP.

> I would apreciate any comments and ideas -- I've just recently begun
> thinking about this and could possibly be fundamentally wrong about
> something.

This is my little buggy signature...				Pavel
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