mapping files to objects

[Kelly Murray]

> How does each process keep providing service while checkpointing is
> occuring?  Even with a multithreaded implementation, I don't see how
> this could be done without a stopping the world and a painful
> intrusion. It seems like redundant archivers would be needed to help
> ensure that service would always be available (and as soon as there
> are multiple processes, there is the problem of consolidating the
> information they are archiving).

The service will have to go down temporarily.
This isn't any problem at all for SMTP.  /usr/lib/sendmail itself is often
"down" when it gets too busy.  That's just part of the mail protocol,
if you can't connect, you try again a little later.
In any case, we're talking about developing code that works,
not building a production mail system, at least at this point.

-kelly "can do" murray