*BSD News Article 66300


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From: nate@trout.sri.MT.net (Nate Williams)
Newsgroups: comp.os.linux.development.system,comp.unix.bsd.386bsd.misc,comp.unix.bsd.bsdi.misc,comp.unix.bsd.netbsd.misc,comp.unix.bsd.freebsd.misc,comp.os.linux.advocacy
Subject: Re: Historic Opportunity facing Free Unix (was Re: The Lai/Baker paper, benchmarks, and the world of free UNIX)
Date: 17 Apr 1996 15:45:00 GMT
Organization: SRI Intl. - Montana Operations
Lines: 42
Message-ID: <4l33ls$416@helena.MT.net>
References: <4ki055$60l@Radon.Stanford.EDU> <31702487.420C2193@lambert.org> <yfg3f67giw7.fsf@time.cdrom.com> <31718ED3.555EB900@lambert.org>
Reply-To: "Nate Williams" <nate@sneezy.sri.com>
NNTP-Posting-Host: trout.sri.mt.net
Xref: euryale.cc.adfa.oz.au comp.os.linux.development.system:21730 comp.unix.bsd.386bsd.misc:681 comp.unix.bsd.bsdi.misc:3312 comp.unix.bsd.netbsd.misc:3148 comp.unix.bsd.freebsd.misc:17640 comp.os.linux.advocacy:46189

In article <31718ED3.555EB900@lambert.org>,
Terry Lambert  <terry@lambert.org> wrote:
>]    Now let's talk about "magic install images".  Such an image is
>]    a non-memory-overcommit (fd's are not strictly recoverable for
>]    executables) APM save image of a sytem "just about to be
>]    installed".
>] 
>] I'd need to see a prototype of this before I could even begin to
>] believe there weren't 500 different "gotchas" still waiting to spring
>] on the unwary implementor.
>
>Nate Williams already has a prototype.  It's called the APM code
>from the "BSD Nomads" group in Japan, and his own contributions
>to the APM code and source integration.
>
>Fundamentally, there is no difference betwen restoring machine
>state from a disk image of saved state of the same machine, and
>that of a different machine.

Umm, just to let everyone know (Terry and I already had this discussion
in private email), the code I wrote plus the code from the Nomad doesn't
contain any way of restoring the 'state' of the system from a disk
image.  Some laptops have this feature (an older IBM ThinkPad does, and
my newer NEC Versa doesn't), but it's not part of the 'official' APM
specification.  IBM provides a driver to do this under DOS/Windows 3.1,
but no such driver exists for WNT/Win95, so this isn't possible w/out
manufacturer support under other OS's.

>Not having looked at the APM code, I can only say that from past
>experience with Nate's code, I find it highly unlikely that he
>has built his state-recovery code to be machine specific.

While I appreciate the flattery, no such code exists, and I don't see
myself writing any of it, machine specific and/or independant.


Nate
-- 
nate@sneezy.sri.com    | Research Engineer, SRI Intl. - Montana Operations
nate@trout.sri.MT.net  | Loving life in God's country, the great state of
work #: (406) 449-7662 | Montana.
home #: (406) 443-7063 | A fly pole and a 4x4 Chevy truck = Heaven on Earth