Path: utzoo!attcan!uunet!husc6!rutgers!cmcl2!adm!smoke!gwyn
From: gwyn@smoke.BRL.MIL (Doug Gwyn )
Newsgroups: comp.unix.wizards
Subject: Re: Process restart.
Keywords: Fork, Process, migration, remote, a.out, core
Message-ID: <8880@smoke.BRL.MIL>
Date: 14 Nov 88 08:40:35 GMT
References: <16@elgar.UUCP> <8831@smoke.BRL.MIL> <17@elgar.UUCP> <8857@smoke.BRL.MIL> <18@elgar.UUCP>
Reply-To: gwyn@brl.arpa (Doug Gwyn (VLD/VMB) <gwyn>)
Organization: Ballistic Research Lab (BRL), APG, MD.
Lines: 14

In article <18@elgar.UUCP> ag@elgar.UUCP (Keith Gabryelski) writes:
>Let's say we have this process computing prime numbers (or some other
>simple case) and the system needs to be shutdown because of some fatal
>error.  Can a snapshot be done?

Well, now that you're restricting yourself to the "doable" cases,
these are the sort of programs for which I make them periodically
write out useful intermediate stuff that they can later use to
resume, PORTABLY without needing any special help from the system,
linker, etc.  In fact I had one of these I ran at night on Rice's
IBM 1620 back in 1968; when someone else wanted to use the machine
he could just flip a sense switch and the program would soon punch
out an intermediate set of data that I used next time to continue
the job where it had been interrupted.  Ah, for the good old days.