This from one of the XFS authors. I believe the reason is because XFS is metadata-only so there isn't any journalled data; overwrites of data blocks don't move anything. I believe this is true of JFS and ReiserFS as well but should be confirmed. The only FS I know of for GNU OSes that can journal data is ext3, and even there the common journalling option is metadata-only.
----- Forwarded message from Steve Lord <[EMAIL PROTECTED]> ----- From: Steve Lord <[EMAIL PROTECTED]> Subject: Re: security and journaling To: Ray Muno <[EMAIL PROTECTED]> Cc: [EMAIL PROTECTED] X-Mailer: Ximian Evolution 1.0.8 Date: 30 Sep 2002 14:29:27 -0500 On Mon, 2002-09-30 at 14:18, Ray Muno wrote: > SHRED(1) FSF SHRED(1) > > NAME > shred - delete a file securely, first overwriting it to > hide its contents > > SYNOPSIS > shred [OPTIONS] FILE [...] > > ...stuff deleted > > CAUTION: Note that shred relies on a very important > assumption: that the filesystem overwrites data in place. > This is the traditional way to do things, but many modern > filesystem designs do not satisfy this assumption. The > following are examples of filesystems on which shred is > not effective: > > * log-structured or journaled filesystems, such as those > supplied with > > AIX and Solaris (and JFS, ReiserFS, XFS, etc.) If shred just overwrites in place it will be effective with XFS, that man page is wrong. Steve -- Steve Lord voice: +1-651-683-3511 Principal Engineer, Filesystem Software email: [EMAIL PROTECTED] ----- End forwarded message ----- -- Questra Desktop and Network services (QDN) | (585) 381-0292 x1234 https://qdn.web.questra.com/supportform.php | [EMAIL PROTECTED] _______________________________________________ Bug-fileutils mailing list [EMAIL PROTECTED] http://mail.gnu.org/mailman/listinfo/bug-fileutils
