[9fans] Plan 9

["rob pike" <rob@plan9.bell-labs.com>]

The original reason behind Plan 9 is still the most important and,
unfortunately, is largely obscured by the need to make a distribution
and the desire for individuals to run it on PCs: a shared environment.
We boot all our machines in the lab over the network; they have no
local state except a configuration file (plan9.ini) usually held on a
floppy.  When I go home, my environment - that is, the working state
of my machine - is identical not only with my environment at work, but
with all my colleague's working state, too.  Diskless operation is not
only possible, it's the basic principle of the system.  It's just like
the good old timesharing days: our machines are *terminals* to a large
computing system; whatever machine I sit down at to work, I have
equivalent access to identical resources.  It's more than diskless,
it's transparent statelessness.

Local administration?  What's that?

Sure, with NFS you can get somewhere close to that ideal, but then why
are there so few truly diskless Unix systems out there?  One reason is
that the storage file system isn't enough: the environment includes a
huge array of other machines with special local services
(authentication, printing, backup, connections to other OSs and
networks, etc.)  and the NFS model doesn't permit a general enough
notion of file.  Plan 9 does.  That's the true joy of it.

-rob