Re: Which fs is a good example for learning ?

[Matthew Wilcox <matthew@wil.cx>]

On Tue, Jan 06, 2009 at 09:46:04AM +0100, Francis Moreau wrote:
> That's what I think too but wasn't sure ext2 is still a good choice since it's
> pretty old and it looks like some younger fs seems to make ext2 obsolete.
> Also, it doesn't have a journal.

This is all true.  It depends what your real goal is here.  If you want
to learn the fundamentals of what a filesystem has to do to get blocks
from disc and turn them into files, ext2 is perfect for your needs
since it _doesn't_ have a journal or btrees or any of that fancy stuff.
You can learn that later once you have the principles down.

If your goal is to learn how an advanced filesystem works, you might want
to consider looking at JFS which has journals, extents, acls, xattrs and
so on.  It's around 4x as big as ext2, but then it's also about 1/3 the
size of XFS (just in terms of wc -l).  It's also been properly ported
to Linux, unlike XFS which is still full of IRIXisms.

-- 
Matthew Wilcox				Intel Open Source Technology Centre
"Bill, look, we understand that you're interested in selling us this
operating system, but compare it to ours.  We can't possibly take such
a retrograde step."