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Re: some newbie questions


>>>>> CJ  writes:

 CJ> hello, I was just reading you Debian GNU/HURD web page and I am
 CJ> really confused about the term OS and kernel.

Understandably... not everybody involved with Debian GNU/Hurd has
settled down on a common terminology.

 CJ> For sure, I know that "Linux" is a kernel and "Debian GNU/Linux"
 CJ> is an OS that ported on the "Linux" kernel.

Exactly.  Debian GNU/Linux is the Debian distribution of the GNU OS
running on the Linux kernel.

Debian GNU/Hurd is the Debian distribution of the GNU OS running on
the Hurd kernel servers and Mach microkernel.

 >>>> But what about "HURD", is it an OS or is it a kernel like Linux?
The GNU Hurd is a set of kernel servers that run on top of a
microkernel (Mach).  The ``Hurd OS'' is a misnomer that just causes

The architecture of the GNU Hurd is that it is a set of programs that
run on top of the Mach microkernel.  The GNU Hurd and Mach together
are a replacement for a standard kernel such as Linux.

The problem you're running into is a gap in the existing terminology.
You cannot really consider the Hurd in isolation, because it is
middleware between the C library and the microkernel.  ``Kernel
servers'' is the best term I've heard for what the Hurd is.

You can get more clues from the mutually-recursive acronyms that the
``Hurd'' stands for:



The keywords are ``daemons'' and ``interfaces.''  The Hurd is both a
set of interfaces, and the daemons that implement those interfaces to
support real applications.

 >>>> Also, what is the different between a kernel and a microkernel?

A microkernel is a kernel which attempts to provide a minimal set of
machine-dependent services that are useful for building a ``real
kernel''.  A ``real kernel'' provides things that are useful to
applications, such as filesystems, networking, etc.

All of the above just reflects my understanding of the situation... I
don't claim to have the best words for answering your questions, and
I'm sure other people will add what they know to the discussion.

I hope this helps,

 Gordon Matzigkeit <gord@fig.org> //\ I'm a FIG (http://www.fig.org/)
    Lovers of freedom, unite!     \// I use GNU (http://www.gnu.org/)
[Unfortunately, www.fig.org is broken.  Please stay tuned for details.]

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