plan 9 and linux

plan 9 and linux

[Nigel]

> From:          forsyth@plan9.cs.york.ac.uk
> Date:          Wed, 5 Apr 1995 06:15:10 -0400
> To:            9fans@cse.psu.edu
> Subject:       plan 9 and linux
> Reply-to:      9fans@cse.psu.edu

> >>How is it compared to Linux?
> 
> apples and galaxies.
>
...
 
> if you want a fairly conventional X11/Unix environment on your PC, Linux
> is a reasonable choice.  Plan 9 has different aims.
>
Arrggh. Don't remind me. Roll on the general release! 

plan 9 and linux

[Charles]

   I've been thinking about it and I cannot recall any other system
   that is shipped in one piece to run on a wide variety of platforms.

NetBSD is such a system, and it runs on a wider range of hardware than
Plan 9.

plan 9 and linux

[Greg]

Rob Pike wrote:
> I may be wrong, but every other system I can think of is built for
> one system and then ported to another; with Plan 9, the system is
> carried along together for all architectures, compiled from one
> source tree, etc.

BSD 4.4 (and, more practically, NetBSD) has the same properties--a
single source tree which compiles for seven or so different platforms.
There are still pieces that need to be made more architecture-
independent (e.g. the console driver), butbut it's still one system that
runs on a variety of different architectures.  I'm afraid Xwindows
won't compile for BSD 4.4 in four seconds, though.

Just a note.  There may be Mach-based operating systems with this
property as well, depending on your definitions.

plan 9 and linux

[rob]

Forsyth missed one important difference.  Plan 9 is not a PC operating
system, although it works on a PC.  As shipped, Plan 9 runs on four
instruction architectures (SPARC, MIPS, 68020, 386), with machines
from many vendors (Sun, SGI, Next, Mips, AT&T, and endless PC's).
The PC is an important platform for the system, but not the only one.
I've been thinking about it and I cannot recall any other system
that is shipped in one piece to run on a wide variety of platforms.
I may be wrong, but every other system I can think of is built for
one system and then ported to another; with Plan 9, the system is
carried along together for all architectures, compiled from one source
tree, etc.  It's really one system that runs on a variety of hardware,
rather than different versions with a common ancestor.

A related property is that it is configurable to run on anything from
a laptop to a network of multiprocessor servers.

So comparing it to Linux makes sense only for a narrow subset of
what the system is capable of.

For the record: in our lab version of the system, somewhat different
from what's going out, the window system compiles from C into
a ready-to-go executable in 4 seconds.  I don't think Linux can do
that.

plan 9 and linux

[Dirk]

--PART-BOUNDARY=.19504051818.ZM12227.weser
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Hello,

On Apr 5,  6:15am, forsyth@plan9.cs.york.ac.uk wrote:
> Subject: plan 9 and linux
> >>How is it compared to Linux?
>
> outside the kernel, linux -- reasonably enough for
> a unix/posix clone -- simply uses all the freely available software
> for Unix-like systems that anyone can be bothered to port.  a lot
> of that is Big and Complicated.  by contrast,  although many of the
> older Unix commands are in Plan 9 at least in name,
> Plan 9's commands are freshly written.  (the few things left from the a=
ncien
> r=C3=A9gime -- notably `troff' -- have at least had a facelift.)
> a lot of crufty crud has been left behind.
>
> if you want a fairly conventional X11/Unix environment on your PC, Linu=
x
> is a reasonable choice.  Plan 9 has different aims.
>
>-- End of excerpt from forsyth@plan9.cs.york.ac.uk
[good statements deleted]
Yes, but how about connectivity of plan9. May i able to run it from home
with a slip/cslip/ppp dialup connection. uucp news/mailfeed? News / Mail
reader available?  What's the price for a private person?
Is there a gcc? I'm using a oberon2 -> gnu c compiler, and would miss it
a lot.

Cheers,

Dirk

-- =

"It's 206 ms to Chicago, we've got a full disk of GIFs, half a meg of =

 hypertext, it's dark, and we're wearing sunglasses."
                             "Click it." -- <bluesbros@bluesbros.com>

--PART-BOUNDARY=.19504051818.ZM12227.weser--

plan 9 and linux

[forsyth]

>>How is it compared to Linux?

apples and galaxies.

they do different things.  linux is a self-contained operating
system that can attach to a network.  plan 9 really is a distributed system.

Linux now seems to attempt to track Posix closely, with all that that entails.  
by contrast, although plan 9 has useful ansi/posix emulation environments --
and that's certainly convenient when importing or exporting Unix programs --
it's definitely not the most sensible way of using plan 9.
it isn't a `leaner unix'.  indeed, if you approach it that way,
you will probably be disappointed.

plan 9 provides a number of components that can be put together on a network to form
one (secure, distributed) computing system;  even an apparently `standalone'
plan 9 system at home can link itself smoothly to the name space --
and thus processors, devices and network interfaces -- of a bigger system.

although linux does very well -- the leanest and most effective
unix-like system on a PC -- in my experience, plan 9 easily is less demanding of hardware than
other general purpose operating systems on any given platform.

for instance, at work my terminal is a 386sx/16 with 4mbytes
with an ET4000 ISA graphics card and NE2000 card.  i have a small slow
seagate IDE disc for booting & paging, but it doesn't page much.
at the moment this pathetic machine is running 30 processes
including the window system 8½, seemail, `cpu' to the cpu server
samterm (to remote sam on the CPU server), a local 8½ window for commands,
dossrv (makes DOS file systems on disc & floppy visible in the plan 9 name space),
and supporting commands (eg, kernel protocol processes, exportfs exporting
the terminal's name space to the cpu server).  (by the way, i can access
the terminal's diskette device and/or DOS file system transparently
from the cpu server, just as i access the terminal's keyboard, mouse and screen.)

here is a ps:

forsyth       1    0:00   0:00    40K Wait     init
bootes        2    0:00   0:00     0K Wakeme   alarm
bootes        3    0:06   0:00     0K Wakeme   ether0kproc
bootes        4    0:00   0:00     0K Wakeme   tcpack
bootes        5    0:00   0:00     0K Wakeme   tcpflow
bootes        7    0:00   0:00     0K Wakeme   ilack
forsyth       8    0:00   0:00     0K Idle     pager
forsyth       9    0:08   0:25   352K Read     8½
forsyth      13    0:01   0:02    48K Read     cs
forsyth      17    0:00   0:00     0K Wakeme   floppy
forsyth      23    0:00   0:00   704K Read     dossrv
forsyth      26    0:00   0:00    40K Read     arpd
forsyth      28    0:00   0:00     0K Wakeme   uart0
forsyth      36    0:00   0:01   196K Read     8½
forsyth      38    0:00   0:01   196K Read     8½
forsyth      47    0:00   0:00   132K Read     samterm
forsyth      49    0:00   0:00    20K Read     rx
forsyth      52    0:00   0:00   124K Read     samterm
forsyth      53    0:00   0:01   124K Read     samterm
forsyth      54    0:00   0:00   124K Read     samterm
forsyth      55    0:00   0:00   124K Read     samterm
forsyth      58    0:00   0:00    20K Read     rx
forsyth      59    0:00   0:00   108K Read     seemail
forsyth      65    0:00   0:00    28K Wait     cpu
forsyth      66    0:00   0:01   332K Read     exportfs
forsyth      67    0:00   0:00   332K Rendez   exportfs
forsyth      68    0:00   0:00   332K Read     exportfs
forsyth      70    0:00   0:00   104K Wait     rc
forsyth      75    0:00   0:00    32K Read     ps

is it paging frantically?

term% cat /dev/swap
374/416 memory 92/4000 swap

no: in fact the pager is currently idle.  presumably it has turfed out
most of dossrv since i'm not using it.  (the memory sizes above
can't just be added up: there's a lot of shared text & data there.)

now, you definitely don't want to compile much on this thing -- for one
thing it hasn't got a floating-point unit -- and it's certainly not
as snappy as a bigger 486 at home with more memory and a reasonable graphics card.
nevertheless: try getting an X server to run on a similar configuration
with several xterms, rlogins (inadequate substitute for `cpu'), a mail monitoring
window, and samterm.  it's certainly true that you'll stand the best
chance of doing it with linux, though, compared (say) to solaris/486.

although i haven't made a complete study of linux,
i'd say the system interfaces in the plan 9 cpu/terminal kernel are simpler yet more general than
those in Linux; perhaps more importantly, the plan 9 kernel was
intended to be portable, and support multiprocessors from the start.

aside: there's currently a lot of ignorant hype in the media
about the brilliance of having a Hardware Abstraction Layer in making a certain
o/s portable, but it's really no big deal.  like older portable operating systems,
plan 9's portability interface is a small collection of functions and
data structures.  no fuss.

outside the kernel, linux -- reasonably enough for
a unix/posix clone -- simply uses all the freely available software
for Unix-like systems that anyone can be bothered to port.  a lot
of that is Big and Complicated.  by contrast,  although many of the
older Unix commands are in Plan 9 at least in name,
Plan 9's commands are freshly written.  (the few things left from the ancien
régime -- notably `troff' -- have at least had a facelift.)
a lot of crufty crud has been left behind.  after all, as andrew hume once put it:
``crud that isn't paged in is still crud''.

still, that's old stuff; worthy but dull.
the really interesting bits are the new things, including:

	the protocol 9P that binds everything together
	the file server, and its `dump' file system
	per-process name space
	union mounts
	Unicode
	user-level file servers
	shared memory multiprocess servers, using lean (threadbare?) processes
	cpu
	the window system 8½
	Acme (is that named after the Acme Construction Co. in the Roadrunner cartoons?)
	FAST C compilers; simpler C library interface, and
		every compiler is a cross compiler
	simple support for multiple target architectures
	the concurrent programming language Alef
	acid
	for the administrator: a coherent approach to describing a network,
		and best of all from my point of view, it hasn't got BIND.

if you want a fairly conventional X11/Unix environment on your PC, Linux
is a reasonable choice.  Plan 9 has different aims.