Ultrix-11

[Warner Losh]

On Fri, Aug 20, 2021, 2:26 PM Peter Allan via cctalk <cctalk at classiccmp.org>
wrote:

> The idea of using an RA81 drive as it is bigger sounds like a simple
> solution, but does it actually give a larger /usr partition? Even though an
> RD54 drive is not huge, most of it is not taken up by the root partition
> plus the /usr partition, but is available for use as (on the video at
> least) /user1.
>
> I will give it a try after the weekend and see what happens.
>

I was going to try tonight. The dksizes.c table suggests that it is 10MB
instead of 8.5MB on the RD54. Yet someone else said it was smaller, so I
wanted to check....

Warner


Cheers
>
> Peter Allan
>
> On Fri, 20 Aug 2021 at 17:38, Ethan Dicks <ethan.dicks at gmail.com> wrote:
>
> > On Fri, Aug 20, 2021 at 11:50 AM Peter Allan via cctalk
> > <cctalk at classiccmp.org> wrote:
> > > I just installed Ultrix-11 3.1 using the ultrix31.tap file from
> > > https://pdp-11.org.ru/files.pl?lang=en
> > > which is the location from the comments in Stephen's Machine Room video
> > on
> > > YouTube that I think started this thread.
> > >
> > > It installed just fine, but just like the video, I ran out of space on
> > /usr.
> >
> > /usr was usually tight back in the day.
> >
> > > How can I make a larger /usr partition? Is it possible to do this at
> > > installation time? There did not seem to be an option for this. Can it
> be
> > > done by using an additional disk? That would seem likely, but not what
> a
> > > system manager back in the 70's or 80's would expect to need to do,
> > > especially as there is a relatively large amount of space left to
> create
> > > /user1.
> >
> > In the 70s and early 80s, it was not at all uncommon to have multiple
> > disk drives mounted to add up to enough space, especially to put user
> > files on their own device to keep them from competing with free space
> > in the system areas.  Also, older, smaller disks were often cheaper
> > than the newest/largest disk drives, or systems would be put together
> > from repurposed hardware rather than purchasing new.  For a single
> > data point, my employer bought a new RA81 in 1984.  For 424MB it was
> > $24,000.  Most machines had a _lot_ less disk in those days.  Our main
> > UNIX machine was an old 11/750 (2MB RAM) with 2x RK07 (28MB each).  It
> > was quite a jump when I put Ultrix 1.1 on an 11/730 w/RB80.  The CPU
> > was 30% slower, but it had 5MB of RAM and a 121MB disk, so as a
> > machine that spent most of its time with a single user (me), it was
> > fine.
> >
> > When disks were routinely 1-30MB (RK05... RK07 or RP03), it was
> > totally common to have 2-3 disks on a machine.
> >
> > All that said, I looked over this install write-up and it seems to
> > assume you have one disk and it slices and dices with default sizes...
> >
> >
> >
> http://ftp.fibranet.cat/UnixArchive/Distributions/DEC/Fred-Ultrix3/setup-3.1.txt
> >
> > I've installed older versions of UNIX where you had to explicitly set
> > up disks and partitions (where you _could_ resize partitions).  Prior
> > to restoring the contents from tape.  That didn't appear to be as easy
> > with this installer script.
> >
> > > I noted the options for installing software using soft links to other
> > > locations. Was that the preferred method when installing additional
> > > software?
> >
> > That was done, as was mounting an entire second disk for /usr.  One of
> > the challenges is making sure you have enough tools accessible on the
> > boot device to bring the machine up far enough to mount the additional
> > devices.  This is part of why there are system tools in /bin,
> > /usr/bin, etc.  You could depend on the contents of /bin being there
> > before /usr was mounted.  Also, traditionally, programs in /bin were
> > statically linked so that you didn't have to have specific libraries
> > available at the time.
> >
> > The simplest solution, of course, is just get a bigger disk, but where
> > that wasn't possible (which was most of the time), people did use soft
> > links or multiple spindles to aggregate enough space to get by.
> >
> > Back in the day, I struggled to get enough disk space to install
> > 2.9BSD on an 11/24.  Two RK07s would have been a luxury.  I had an
> > RL02 (10MB) and I think maybe an RL01.  I could get the initial
> > restore to work but I didn't have enough space to rebuild my kernel.
> >
> > -ethan
> >
>