Re: Re: [gentoo-user] How to shred without deleting /dev/*

Re: Re: [gentoo-user] How to shred without deleting /dev/*

[Michael Kintzios]

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> From:: Renat Golubchyk <ragermany@gmx.net>
> To: gentoo-user@lists.gentoo.org
> Subject: Re: [gentoo-user] How to shred without deleting /dev/*
> Date: Mon, 29 Aug 2005 14:35:28 +0200
> 
> Why was it deleted? Did you run the command as root?

Well, yes because when I run it as a plain user I am denied access:
====================
$ shred -u -v /dev/fd0
shred: /dev/fd0: Permission denied
====================

> What's wrong with good old dd? How about
>   $ dd if=/dev/zero of=/dev/fd0
> You can also use /dev/random if it has to be more secure. For even more
> security run it multiple times in a loop.

There's nothing wrong with dd, but I see no reason to create my own script to extend the basic dd functionality.  I would rather use shred which does everything I want it to do - if only I can avoid the deletion if the device node itself.
-- 
Regards,
Mick

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Re: [gentoo-user] How to shred without deleting /dev/*

[Sergio Polini]

Michael Kintzios:
> There's nothing wrong with dd, but I see no reason to create my own
> script to extend the basic dd functionality.  I would rather use
> shred which does everything I want it to do - if only I can avoid
> the deletion if the device node itself.

Why -u?
>From the man page:

========
Delete FILE(s) if --remove (-u) is specified.  The default is not to
remove  the  files because it is common to operate on device files
like /dev/hda, and those files usually should not be removed.
========

BTW, which is your filesystem? From the man page again:

========
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, Ext3, etc.)
========

HTH
Sergio



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Re: Re: [gentoo-user] How to shred without deleting /dev/*

[Michael Kintzios]

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> From:: Sergio Polini <sp_rm_it@yahoo.it>
> To: gentoo-user@lists.gentoo.org
> Subject: Re: [gentoo-user] How to shred without deleting /dev/*
> Date: Mon, 29 Aug 2005 15:09:36 +0200

> Why -u?
> From the man page:
> 
> ========
> Delete FILE(s) if --remove (-u) is specified.  The default is not to
> remove  the  files because it is common to operate on device files
> like /dev/hda, and those files usually should not be removed.
> ========

Oops, I brushed over it too fast and missed this rather important point!  So, the -u option should NOT be used on devices.  ;-)  Thanks Sergio!
-- 
Regards,
Mick

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