Re: dd: it doesn't continue after errors

[Pádraig Brady]

On 12/28/2012 04:29 PM, Bernhard Voelker wrote:
> On 12/28/2012 12:41 PM, YuGiOhJCJ Mailing-List wrote:
> > I am trying to blank a 160 GB hard disk drive but I got an error and dd doesn't 
> > want to continue:
> > $ sudo dd if=/dev/zero of=/dev/sdb conv=noerror,sync
> > dd: writing to `/dev/sdb': Input/output error
> > 6160537+0 records in
> > 6160536+0 records out
> > 3154194432 bytes (3.2 GB) copied, 209.528 s, 15.1 MB/s
> >
> > Only 3.2 GB have been copied...
> >
> > Have you any idea on how to force dd to continue after errors?
>
> You mean your hard disk is dying and you want to overwrite it with NULs?
>
> As you most probably will throw it away anyway, why not
> simply use a hammer to destroy your sensitive data?
> And maybe using a huge magnet before or after that ... ;-)

Oops right, the issue seems to be with writing to the dodgy disk.
conv=noerror,sync confused me since this is only concerned with reading.
Anyway I had a look at shred.c and noticed this comment:

/* 'shred' is often used on bad media, before throwing it
    out.  Thus, it shouldn't give up on bad blocks.  */

So shred is probably the best tool for this.
You can get shred to write just NULs like:

shred -n0 -z -v /dec/sdb

thanks,
Pádraig.