FS / inode / vnode refresher

Tue Jun 15 14:54:48 PDT 2004

Re: your last question, Google is your friend.

http://www.cs.utk.edu/~plank/plank/classes/cs360/360/notes/Dup/lecture.h
tml

The difference between a vnode and an inode is where it's located and
when it's valid. Inodes are located on disk and are always valid because
they contain information that is always needed such as ownership and
protection. Vnodes are located in the operating system's memory, and
only exist when a file is opened. However, just one vnode exists for
every physical file that is opened.  

----
David Smith <dsmith at financialengines.com>
Voice: 650-565-7750 Fax: 650-565-4905 

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-----Original Message-----
From: Roy S. Rapoport [mailto:rsr at inorganic.org] 
Sent: Tuesday, June 15, 2004 2:44 PM
To: baylisa at baylisa.org
Subject: FS / inode / vnode refresher

I've been a sysadmin for about 12 years now, and have a pretty decent
understanding of most things sysadmin.  I've got enough of an
understanding
of how the UNIX filesystem works to explain, say, how files are stored,
in
general, what inodes are, and what the diff between symlinks and hard
links
is.  

I need to bone up on the lower-level details for an interview next week.
Having already done this on the network side (TCP/IP Illustrated is your
friend), I'm looking for refresher material on filesystem organization,
hopefully at a similar level (in other words, I'm looking for something
deeper than "a directory contains a bunch of files" and something a
little
more relevant and high-level than "here's the code to directly
manipulate
inodes").  At the same time, I have to shamefully admit that I'm trying
to
figure out what the difference between an inode and a vnode is
(remember,
there are no stupid questions, only stupid people).  

Any pointers?

-roy