[rescue] s/390 primary/secondary, multi-level, real/extended, swap, etc.

[Greg A. Woods]

[ On Wednesday, February 6, 2002 at 16:26:25 (-0500), Julius Sridhar wrote: ]
> Subject: Re: [rescue] SS10/20 death
>
> On Wed, 6 Feb 2002, Eric Dittman wrote:
> 
> > > > How did you manage to afford such a machine for yourself?
> > >
> > > I got it from an idiot who thought because it's big, it has to be old.  I
> > > paid $2000 for it.
> > >
> > > > Also, I'm assuming that the 16GB is ram, and you say the 6TB is disk.  What
> > > > exactly is the 128GB then?
> > >
> > > Multi-level RAM.
> >
> > Real and Extended is what the system calls it.
> 
> Actually, it depends on the OS.

Yeah -- I suspect under Unix it would be called "swap".

I dunno about the S/390, but older IBM mainframes often had not just
completely separate paging devices, but they were often even of quite
different design (and well they should be -- the job of paging virtual
memory is quite different from that of supporting a random-access
filesystem of most any kind).

In the really olden days "primary memory" was core, "secondary storage"
was disk, and "offline storage" was tape.  Before disk there was drum,
and before that there was pretty much only tape (and mercury delay
lines, storage scopes, etc., though each of those was more like a CPU
register -- even early drums were used more like registers)

-- 
								Greg A. Woods

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