Index

1. Plan 9 from Bell Labs

• MOVIE GOOFS AND INTERESTING FACTS LIST
          Version 3.9 (October 1993)
  A collection of film flubs, cinematic slip-ups,
  movie mistakes, Hollywood howlers, etc etc.
  Compiled by Murray Chapman and Michael Gaines
        (render1@teak.njit.edu)
     Found by the users of USENET.
  
  
  # Plan 9 from Outer Space
  - Bela Lugosi died two days into the
    shooting of this turkey.
    He was replaced by the director’s
    wife’s chiropractor,
    who was significantly taller than Lugosi,
    and played the part with a cape
    covering his face.
  - Internationally recognised as the worst
    movie ever made.

2. Plan 9 from Bell Labs

• Plan 9 from Bell Labs is a network operating system and it is composed of separate machines acting as
  • CPU servers
  • file servers
  • terminals
• it is built from distinct specialised components
  • rather than similar general purpose components
• high performance general purpose components cost a lot of money
  • workstations is too slow and IO bound for fast compilation
  • too expensive just to be used as a windowing system

3. Plan 9 from Bell Labs

• Plan 9 approach is based on distributed specialisation would better address issues:
  • cost effectiveness
  • maintenance
  • performance
  • reliability and security

4. Plan 9 from Bell Labs

• radical steps taken
  • build a completely new system
  • C compiler, operating system, network software, command interpreter, window system and terminal!
• authors credentials?
  • Rob Pike - famous for many of UNIX concepts during the early years
  • Ken Thompson - wrote the first C compiler. Then worked on translating UNIX from assembler to C
  • AT&T - birth place of UNIX - so wealthy that the USA divided AT&T into two because of its power

5. Plan 9

• different from other research and commercial operating systems. It lacks features often associated with other research network operating systems
  • process migration
  • lightweight processes
  • distributed file caching
  • personalised workstations
  • support for X windows

6. Plan 9

• built around CPU servers (large multiprocessors)
  • file servers
  • terminals (bitmap screen, mouse & computer running a window system 8 1/2)
• sharing of computing and storage services provide a sense of community for a group of programmers
  • cost effective
  • simplifies management and administration

7. CPU Servers

• in 1990 the production CPU server was a Silicon Graphics Power Series machine with four 25 MHz MIPS processors
  • 128 Mbyte memory
  • no disk
  • 20 Mbyte/sec DMA interface to the file server
  • Ethernet network interface

8. CPU Servers

• operating system has conventional process model using
  • fork
  • exec primitives
• new processes are run on a new processor whenever possible (similar to Amoeba in this respect)
  • processors similar to disk blocks
  • buy more disk space when you run out
  • buy more processors as well
• CPU servers have no local disk

9. File Servers

• Plan 9 file server is a modest
  • two processor
  • 64 Megabyte of memory
  • 600 Megabytes of hard disk
  • 300 Gigabyte juke box of write-once optical disk (WORM)
• it interfaces to the CPU servers through the 20 Mbyte/sec DMA links

10. File Servers

• file server interfaces to other terminals through conventional networks
• file server presents a file system to its clients not an array of disk drives
  • different from Windows in this respect. cf a: b: c: d: e: f:

11. File Server (continued)

• file system actually resides on WORM
  • the modest 600 Mbyte drive only acts as a cache

• 

12. File Server Security and Backup

• once a day the file tree is frozen and split
  • old files can be accessed through normal file operations
  • /1990/0401/usr/rob/doc/plan9.ms
• this scheme permits users to compare files against old versions using traditional tools applied to a normal file system
  • permissions are the same
  • security remains intact

13. Plan 9 Network Structure

14. GNOT terminal

• specialist terminal whose specification is:
  • 25 MHz 68020
  • 1024x1024 4 colour display
  • keyboard and mouse
  • 4..8 Mbytes of memory
  • 2 Mbit/sec packet switched network connects a GNOT to the CPU servers
• terminal does not handle compilation
  • might run a text editor though

15. Plan 9 GNOT

• cheap enough so that each person can have 2
  • 1 at work
  • 1 at home

16. Plan 9 code size statistics

• window software written from scratch
  • 8 1/2 source is 60K bytes including source for xterm equivalent
  • roughly functionality of X windows (no colour)
  • 3860 lines of code and compiles in 10 seconds
  • compare to X windows!
• Plan 9 is small!
  • the kernel is 3647 lines of C code
  • it takes 10 seconds to compile and 10 seconds to load

Index

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