lkml.org 
[lkml]   [1999]   [Dec]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: Ext3 Filesystem
Hi,

On Mon, 6 Dec 1999 09:24:40 -0500 (EST), "Byron R. Stanoszek"
<byron@hilbert.math.uakron.edu> said:

> My thoughts on ext3:
> When looking into ext3, I thought it would be a completely different file
> system apart from ext2. However, I was surprised to see that most of
> the filesystem is the same except for using that journal.dat file. So I was
> wondering, couldn't this journaling filesystem really just be a flag added
> to one of the reserve bits in the ext2 header that labels it as such?

The filesystem internals have to be substantially changed for
journaling, but the on-disk filesystem *is* just marked by a flag in
the ext2 superblock which indicates that there is a journal present.
You can thus migrate between ext2 and ext3 on disk easily, but you
cannot use the same kernel code to mount ext2 and ext3.

> Also, I've read recently about the problems with root seeing
> journal.dat ... I feel the file shouldn't actually be part of the
> directory hierarchy, but stored within an normally-unaccessible
> portion of the ext2 partition.

The final release will have the journal in a hidden inode.

> From my point of view, I don't see it anything more than being an
> extension of ext2, and I figure once the design is finalized there
> would be options to some e2fs-tools programs to add journaling
> support to an already-existing ext2 filesystem, etc.

There already is. You can also remove journaling from an ext3
filesystem.

--Stephen

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:55    [W:0.067 / U:5.052 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site