[TUHS] RFS was: Re: UNIX of choice these days?

Clem Cole clemc at ccc.com
Sat Sep 30 00:20:26 AEST 2017

On Fri, Sep 29, 2017 at 4:59 AM, Andreas Kusalananda Kähäri <
andreas.kahari at icm.uu.se> wrote:
> My main work setup today is actually a diskless (X11-less) OpenBSD
> ​ ​
> system.

​Please be careful when you compare a technology choice of today with

What Larry and I were arguing about diskless was based on the Masscomp
WS-500 vs Sun-3 vs Apollo system of the same vintage.   Pricing on the 3
systems (with a disk) and the same amount of memory (all three used the
same 16Mhz 68020 processor)  was $9.5K for the WS-500, $10K for the Apollo
and $11.5K for the Sun.   But if you dropped the disk out the system, the
Sun's dropped to $7K and the Apollo's $6.5K (Masscomp could not because I
refused to build it as I thought it was crappy idea for a real time system).

FYI:  Sun charged another $5K for an add-in disk unit, although on
the aftermarket you could get one that worked fine for about $4K [which is
what we did to all the Stellar development systems when we discovered that
they did not work as well as we had thought].

IIRC the memory was 4M (it might have been a little more, but not too
much).    The disk itself was on the order of 100M in size and was ST-506
based on, with an ST-506 to SCSI converter.   I'm trying to remember when
the 200-500M 5.25in ST-506 disk showed up but I think it was a little after

The point is the cost of the HW and configuration of the HW for all intents
and purposes was the same between the three systems.
The difference really was the software.    Each had made different
choices... given their chosen markets.

Today, the HW  allows different choices.  Memory configurations alone, make
diskless much more interesting.   Ignoring a local cache, if you a RAM file
system on a system like what I just described, it took up 1/4 of the memory
you had.

Today, Linux and *BSD use 'ramFS' just to boot the OS - which makes perfect
sense, *today*.

On the other hand, back in the day, on the Masscomp, we turned the cache
off and 'borrowed it' as scratch pad RAM for the boot process (UNIX turned
it on as part of turning on the MMU) because memory was such a premium and
it might not be working.    *Diskless was cost choice in the old days. *
Today the price of the disk (SSD) (i.e. price/bit is so small) the 'cost'
has more to do with power and space in the case and possibly portability
than the price of the bits themselves.   In theory a 'Chromebook' style
system of today needs to permanent local storage.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://minnie.tuhs.org/pipermail/tuhs/attachments/20170929/c61fef18/attachment.html>

More information about the TUHS mailing list