Checkpoint/Restart (was "no subject - file transmission")

[Mike]

>> >Why does this line come to mind: "Do the easy 90% and give it to the
>> >users; do the hard 10% only if they then ask for it."
>> 
>> Why does the thought come to mind "anyone whose application requires
>> only a 90% chance of executing successfully shouldn't be using the
>> computer at all"?

There's a bad assumption there - that a 90% restart facility
automatically means that any given process will automatically restart
only 90% of the time. Try a more realistic assumptiom - 90% of the
processes on the system don't use any facilities that would break
restarting. That means an applications programmer only needs to insure
that the application in question never uses the 10% of the Unix
facilities that don't work under restart. And if that 10% includes
something critical for a lot of people - they can ask for it, and the
hard part can be done.

>> Other operating systems do not have the rich process environment
>> that UNIX provides.  If there are only a small number of things that
>> need to be straightened out in a batch-processing environment, then
>> system-provided checkpointing is feasible.

And I remember people bragging about how cheap and small Unix
processes were. How things have changed.

	<mike