[ILUG] don't ya just hate it when...

[Smelly Pooh]

In reply to Paul Jakma's flatulent wordings, 
> On Thu, 17 May 2001, Smelly Pooh wrote:
> 
> > Anyway Unix is far from sun's 'network is the computer' slogan,
> > surely your OS would need to be distributed to boast that.
> 
> on a serious note...
> 
> yes it would be i guess. although unix gets as close to it as possible
> while still remaining a bunch of distinct computers.. plan9 is
> supposed to distributed - anyone tried it?

Unix doesn't get that close to it at all, it may make access to computers on
the network easy but that's pretty far from the network being the computer.
Plan9 is not a distributed OS, if you had a network of plan9 machines, they
can all be seen as distinct instances of Plan9 (each machine running its own
services with its own address and so on).  Plan9 doesn't do any more
networking/distribution than Linux does, but it does make it more seamless.
Everything, including remote resources appear to Plan9 as files.  That's not
just NFS type files but everything from acessing a remote Plan9 Windows server
as a device file to messing around with the processes on a remote machine by
accessing it's exported /procfs (some people would be happy to know that
network interfaces do exist as files in Plan9).  Inferno follows the same
everything is a file philosophy but runs everything as bytecode in a VM aswell

> So in effect with this scheme a large hardware coherent NUMA machine
> would essentially be X seperate linux kernels (X=# of nodes) running a
> distributed smpfs to coordinate access to memory, IO, inodes, etc..

I don't see how that will make your kernel/kernels any more efficient, you're
basically applying a distributed computing model to parallel computing which
involves more work

> Now imagine one day someone actually implements such a thing for
> linux. The only difference between such a machine and a bunch of PCs
> would be the hardware memory access...
> 
> just one more step of someone writing code to implement the NUMA stuff
> over, eg ethernet or UDP. And hey presto... distributed linux will be
> born.

I think there's more to it than that, for example every piece of hardware
access (not just memory) will have to be dealt with. On a single machine with
multiple kernels each kernel can directly access hardware such as it's network
card or hard drive, if you distribute that over multiple machines, 2 kernels
negotiating access to the network card are unlikely to be talking about the
same network card, in which case they didn't even need to negotiate in the
first place, and it would be erroneous to do so, same applies to the hard
drive and pretty much any other device