Re: dd: it doesn't continue after errors

[YuGiOhJCJ Mailing-List]

On Fri, 28 Dec 2012 17:29:35 +0000
Pádraig Brady <address@hidden> wrote:

> 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.
> 

I have just tried 'shred' and I got an error:
$ sudo shred -n0 -z -v /dev/sdb
[...]
shred: /dev/sdb: pass 1/1 (000000)...149GiB/150GiB 99%
shred: /dev/sdb: fdatasync failed: Input/output error
shred: /dev/sdb: pass 1/1 (000000)...150GiB/150GiB 100%
shred: /dev/sdb: fdatasync failed: Input/output error

What it means?