Ancient UNIX; was Re: [Gllug] loadavg

[Ian Northeast]

Nix wrote:
> On Thu, 27 Jan 2005, Ian Northeast mused:

>>UTS the IP stack is not truly in the kernel, it is built by a script
>>shortly after IPL (boot). There are a number of daemons to support
>>it.
> 
> 
> Microkernellish, or just `this was bodged on the side so we didn't want
> to fit it in the kernel'?

The latter I think. The kernel is 2.4MB, not large by some standards but 
hardly a microkernel. It's not modular.

> 
> 
>>    When the ethernet "cards" it wanted weren't available, the whole
>>lot went tits up. All the daemons failed to start. No IP. Not at all.
> 
> 
> Excellent.
> 
> But since they were in userspace you could start them yourself, I
> hope...

Eventually, once we worked out what the actual problem was. The error 
messages were extremely uninformative.

> 
>>It was only possible to "use" this system because it has excellent SNA
>>support.
> 
> 
> SNA: a term of mythic horror that those who have experienced it recoil
> from. I have not had this epochal experience myself.

Then you will be pleased to know that IBM now make it available for 
Linux:) I have no idea how many people use it. I don't. If I need an SNA 
- TCP/IP bridge I use AIX.

>>         This is why I know the above. I had to log in to a convenient
>>zOS (MVS) machine which does both IP and SNA and hop across via SNA.
>>
>>I did mention that this thing is weird didn't I?
> 
> 
> It's IBM. 

UTS isn't IBM, it was originally Amdahl. That it achieved any popularity 
at all though is, IMO, down to an IBM foot shooting incident. At around 
the same time, AIX/390 was available. But IBM deliberately decided not 
to target it at existing MVS/VM customers and it had no support for 
their 3270 terminals. We, and many another mainframe shop, had a huge 
infrastructure of said terminals and couldn't replace them overnight. 
UTS did support them. That's why we used it instead of the IBM offering 
and I don't think we were alone. It just seems to have taken us a bit 
longer to get rid of it.. The 3270s have been gone for many years now.

Regards, Ian

-- 
Gllug mailing list  -  Gllug at gllug.org.uk
http://lists.gllug.org.uk/mailman/listinfo/gllug