[SunRescue] Cheap big iron

[Greg A. Woods]

[ On Friday, April 6, 2001 at 21:19:52 (+0100), Mike Meredith wrote: ]
> Subject: Re: [SunRescue] Cheap big iron
>
> I don't remember any signs of it (although I'll admit that I wasn't 
> looking --- looking after the Sequents wasn't really my job, just 
> something I did when others weren't available). How many dual-universe 
> Unixes were there ? I can only remember Pyramid's OSX (?).

Yes OSx (not the "datacenter" version, DC/OSx, which was pure SysVr4),
and at least one more....

The more I remember the more I think Dynix (pre /ptx) was one of them.

In some respects AIX-3.x was somewhat dual-universe-like, though it was
more of a big mixed up mess than anything else.

> Someone else has mentioned that Dynix *was* BSD based, and Dynix/PTX 
> was SvR[34] based. Certainly the Dynix/PTX version I worked with was 
> SvR3 based, but perhaps later ones were SvR4 based (and quite possibly 
> wouldn't work on older h/w).

There may have been an interim Dynix/PTX that was just SysVr3, but the
final release most customers were to get was supposed to be pure SysVr4

Well, Dynix had Berkeley TCP/IP and a true V7 /bin/sh suggesting that it
was in fact 4.2BSD.  However if it was dual-universe then my guess it
was a native 4.2BSD kernel with SysV stuff in user-land on the side
because I don't remember any major headaches porting system applications
to it (other than the fact /bin/sh was too ancient for some of our
scripts).

Now Pyramid OSx was a true dual-universe system.  There was a system
call that dumped you in one universe or the other.  Internally the
kernel was almost schizophrenic and you simply could not tell you were
not in an entirely 4BSD or SysV(r2?) universe without looking for a
couple of strange "links" in the filesystem that would let you peek over
into the other universe's files.  It was extremely well done.  So well
done that it drove me absolutley nuts trying to port some systems
applications to it!  *I* wanted to be in both universes at the same
time, especially since one of the applications I was porting was a
security auditing tool.  I ended up having the audit run twice, once in
one universe and once in the other.  DC/OSx was a breath of fresh air!

Back then I really really really really really liked SysVr4!  There was
almost nothing wrong with it in my mind (except the fact that the BSD
compatability package, if still in its raw AT&T form, was purposefully
crippled by having literally broken code in its library).  It solved
many of the problems of running Unix in a production computing
environment.

-- 
							Greg A. Woods

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