multics system - Department of Computer Science

MULTICS SYSTEM
Under the Guidance of:
Submitted by:
Prof. Jan Schaumann
Harshitha S. Anand
CS 615 A: Aspects of System Administration
Stevens Institute of Technology
Spring 2011
News: some very bad and some good
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Tornadoes in Alabama…. And how it affected Internet
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Finally Apple launches white iPhone on Thursday; and also
iPad in Japan
The Royal Wedding : how it crashed BBC website’s live
video feed
http://www.digitaltrends.com/computing/royal-weddingboosts-internet-traffic-crashes-bbc-website/
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Ubuntu releases 11.04 Natty Narwhal……
Overview
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Introduction
History
Features of Multics
Influence on other Systems
Multics v/s UNIX
Why it failed?
Conclusion
References
Introduction
MULTICS: MULTiplexed Information and
Computing System
1964
- Project led by MIT (with Fernando
Corbató(Corby)) along with General Electric
and Bell Labs.
- PL/I was chosen as the programming
language
Introduction
1969
- Bell Labs dropped out in 1969
- Official Launch of Multics
- Ken Thompson drops out of the
project
Introduction
1970
GE's computer business including
Multics was taken over by Honeywell
History
MIT usage (10/69)
• MIT's Multics was finally opened for paying customers in
October 1969, several years later than planned.
Responsibility for running the GE-645 was transferred from
Project MAC to MIT's Information Processing Center.
• Pioneer users of the system put up with a lot: crashes, poor
response, constant change, arrogance from developers, and
inexplicably missing features.
• The Multics developers and the MIT Information Processing
Center management worked furiously to fix problems and
make good on overdue promises, and to stave off
abandonment of the system by ARPA, GE, or large MIT
users
Chronology: http://www.multicians.org/chrono.html
2000
The last Multics system running, the
Canadian Department of National Defense
Multics site in Halifax, Nova Scotia,
Canada, shut down October 30, 2000 at
17:08Z.
This system was modified to be Y2K
compliant and was the main production
system until Sept/00.
Lastly,
Goals
When Multics was first started in 1965
there were Nine major Goals to achieve:
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Convenient remote terminal use.
Continuous operation analogous to power & telephone
services.
A wide range of system configurations, changeable without
system or user program reorganization.
A high reliability internal file system.
Support for selective information sharing.
Hierarchical structures of information for system
administration and decentralization of user activities.
Support for a wide range of applications.
Support for multiple programming environments & human
interfaces.
The ability to evolve the system with changes in technology
and in user aspirations.
[5]
Features of Multics
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Segmented memory
Virtual memory
High-level language implementation
Shared memory multiprocessor
Multi-language support
MRDS Multics Relational Database Store
Security
On-line reconfiguration
Software engineering
Multics in Honeywell
Inside the System
Front view of CPU
Back view CPU
Frontend Network Processor
Look under the
false floor
As a System Admin
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The term SysAdmin was first used on Multics. It comes from
the "project" name used by system administrators. The
system administration software for Multics was written in
about 1969, by Joseph F. Ossanna and Michael J. Spier.[3]
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What was MULTICS's administrative model? Pyramid model
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There are 3 kinds of Sys Administrators [7]
- Unrestricted System admin: register new users, confer
resource quotas
- Restricted Sys Admin: user groups
- Project admin: to manage resource budget within a project
Influence of Multics on other OS
Multics vs. UNIX
How did goals of UNIX differ from those of MULTICS?
UNIX started as Ken Thompson writing something for himself "not
designed to meet any predefined objectives"
1. Done by programmers, so design naturally supported
programmers
2. Severe (64K) size limitations imposed by hardware - Designed
around small component programs (unlike MULTICS VM) - Makes it
easier to unify file/pipe/device I/O abstractions
3. System maintained itself almost from the start - Multics was
eventually maintained on itself. ...but started with very heavy-weight
design/engineering effort. Many components built then integrated
together.
Multics vs. UNIX
What did UNIX inherit from MULTICS?
A shell that executes commands was obviously a big
influence
The idea of a hierarchical file system Probably the readwrite-execute permission bits Device-independent I/O
What did UNIX reject from MULTICS?
Files look like memory: instead, unifying idea is file
descriptor and read()/write() memory is a totally separate
resource
Dynamic linking: instead, static linking at compile time,
every binary had copy of libraries
Segments and sharing: instead, single linear address
space per process
Hierarchical rings of protection
simpler user/kernel
for subsystems, setuid, then client/server and IPC
Why Multics failed?
“Failed” because it was a computer utility
- Ahead of its time – no Internet for access
 Took almost 35 years to evolve from drum memory
to VLSI
 Follow on to Compatible Time Sharing System
(CTSS)
- Too complicated, too costly hardware
- “Second System Effect” term coined by Fred
Brooks
System one was successful (CTSS)
System two aims to correct all flaws from #1
Almost always fails: too bloated, slow, etc
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CONCLUSION
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My encounter with the Legend TVV: Tom Van Vleck
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Never ending research about Multics
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Sad but true that Multics ended its era almost a decade ago….
http://www.cio.com.au/slideshow/325629/slideshow_cio_blast_from_
past_-_40_years_multics/
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Still considered as the most Secure Operating System till date….
References
[1] http://www.multicians.org/multics.html
[2] Thirty Years Later, http://www.acsac.org/2002/papers/classic-multics.pdf
[3] SysAdmin: http://www.wlug.org.nz/SysAdmin
[4] Wikipedia of course, http://en.wikipedia.org/wiki/Multics
[5] Introduction and Overview of the Multics System by Corbató and Vyssotsky
[6] IST, MIT http://web.mit.edu/multics-history/
[7] Multics:The first seven years;
http://web.mit.edu/Saltzer/www/publications/f7y/f7y.html
[8] Myths about Multics: http://www.multicians.org/myths.html
[9] Multics System Images
http://www.vaxman.de/historic_computers/multics/multics.html
THANK YOU!