[mod.os] Article for mod.os

aviel@sdcsvax.UUCP (03/11/87)

In article <2765@sdcsvax.UCSD.EDU>, darrell@sdcsvax.UCSD.EDU (Darrell Long) writes:
> 
> 	I am looking for references on UNIX-based distributed operating
> systems. I would be grateful if you could forward this query to the
> readers of this group. Any implementation or those planned around
> UNIX will be most welcome. Please mail pointers to
> 
	We at National Semiconductor Design Center in Israel have a fully
operational UNIX based distributed operating system.

This system, named NSMOS, is fully compatible with UNIX-5.2. It operates
on several (currently up to 30) independent computers connected via Ethernet,
each having its own resources such as memory, disks, tapes and terminals.

	NSMOS implements dynamic load balancing: Unix processes are migrated by
the kernel while they are running, without the user's intervention or
knowledge.
	Almost pointless to mention that the file system as well as the other
functions of Unix are distributed.

	NSMOS supports distributed applications. Applications with potential
parallelism in UNIX will actually run in parallel on NSMOS. (Yes..
parallel "make" and other alikes).

	The system is dynamically configurable. Processors may join the network
without affecting the already-running processors. Processors may leave the
network in an orderly manner. When a processor crashes, the rest continue in
their operation, and only processes that were connected to the failed
processor or processes that happened to run there are affected.

    Besides processor loads, the load-balancing algorithm takes into account
the cost of remote I/O operations and of the migration itself.
A process that does much I/O on files on a certain processor, will likely
move to that processor.

	NSMOS currently runs on National's series 32000 family architecture,
on National's VR32 (multi-user) development system (with 32332 @ 15MHz).

An original prototype is described in:
"Software Practice and Experience", August 1985:
						"MOS - A multi-computer operating system"

For details write to aviel%nsta%nsc


Darrell Long
Department of Computer Science and Engineering, C-014
University of California, San Diego
La Jolla, California  92093

ARPA: Darrell@Beowulf.UCSD.EDU
UUCP: sdcsvax!beowulf!darrell