From mboxrd@z Thu Jan  1 00:00:00 1970
From: quanstro@quanstro.net (erik quanstrom)
Date: Wed, 23 Mar 2011 09:20:23 -0400
Subject: [9fans] namespaces, Alef
In-Reply-To: <9d5755de-60ad-4f53-87b4-b4b6d19f8858@o21g2000prh.googlegroups.co>
References: <9d5755de-60ad-4f53-87b4-b4b6d19f8858@o21g2000prh.googlegroups.co>
Message-ID: <1137bad2f6e5ac855fd4e0ce23c1c905@brasstown.quanstro.net>
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> a) It seems that the potential of namespaces can be exposed only when
> using a distributed environment with multiple machines (CPU servers,
> file servers, terminals, etc.). Can I get a feeling about what a
> namespace is in practice if I only own a single system installed on a
> virtual machine?

false.

the system would not function without namespaces.

for example, a search path is usually not used.  bin is constructed from
several underlying directories; often /$objtype/bin /rc/bin $home/bin/$objtype
$home/bin/rc.  

the same goes for the construction of /dev.  /dev is constructed from
a number of file servers, such as #c. #P, #$, #S, #r, #i, #m, #v, #u, #t,
#?, #?.

there's no reason you can't write a user-level file system that provides
a "device" that lives in /dev.

ramfs is simple, but perhaps the most consistently useful example.
ramfs mounts a ram disk on /tmp.  then you can scribble away, and
when you're done, you can just delete the window, or unmount /tmp.
you can run many independent ramfs at once.

> b) I know that Limbo is mostly used in Inferno, but is Alef or Limbo
> used in any parts of the native Plan 9? According to wikipedia (http://
> en.wikipedia.org/wiki/Alef_%28programming_language%29) the Alef parts
> were rewritten in C.

true.

- erik