I have just wiped a 250GB drive and didn't want to wait for the default 3-pass process. One pass is slow enough. Having to use -n0 --zero seemed sufficiently un-obvious that I added this example to the manual:
>From 7dc6335653afcdad9a3ffa327877571734644285 Mon Sep 17 00:00:00 2001 From: Jim Meyering <meyer...@redhat.com> Date: Mon, 17 Jan 2011 11:32:35 +0100 Subject: [PATCH] doc: show how to shred using a single zero-writing pass * doc/coreutils.texi (shred invocation): Give an example showing how to invoke shred in its most basic (fastest) write-only-zeros mode. --- doc/coreutils.texi | 9 +++++++++ 1 files changed, 9 insertions(+), 0 deletions(-) diff --git a/doc/coreutils.texi b/doc/coreutils.texi index 9c3e2ed..8fb9f0c 100644 --- a/doc/coreutils.texi +++ b/doc/coreutils.texi @@ -8892,6 +8892,15 @@ shred invocation shred --verbose /dev/sda5 @end example +On modern disks, a single pass that writes only zeros may be enough, +and it will be much faster than the default. +Use a command like this to tell @command{shred} to skip all random +passes and to perform only a final zero-writing pass: + +@example +shred --verbose -n0 --zero /dev/sda5 +@end example + A @var{file} of @samp{-} denotes standard output. The intended use of this is to shred a removed temporary file. For example: -- 1.7.3.5