On Fri, Jan 25, 2002 at 12:35:01PM +0100, Andreas Raab wrote:
> Lex,
> 
> > EROS could do it, however.  EROS is an operating system that
> > automatically pages memory to disk as you run -- very OOZE-like!  EROS
> > is very careful in the order it saves things to disk; at any 
> > time, there is one complete and consistent snapshot, and one
> > snapshot being built. 
> 
> Do you have any pointers to how they do this?! The thing I'm mostly
> interested here is how they deal with any kind of "external" resources
> (e.g., network connections etc).
> 
No idea how EROS does it, but for the rio project it's described in
the Paper 
Lowell, Chen: Discount Checking: Transparent, Low-Overhead Recovery
for General Applications.

http://www.eecs.umich.edu/~pmchen/Rio/papers/discountChecking.ps

"
 TCP: Much of the state used to implement the TCP protocol is
 in the kernel. To acces this state, we omplemented a user-level
 TCP library built on UDP. Since our TCP library is part of the
 process, Discount Checking saves its state automatically. ....
"  (p. 5)


-- 
Marcus Denker marcus at ira.uka.de  -- Squeak! http://squeakland.org