<paulmd@efn.org> wrote in message news:1173925752.221642.270340@e1g2000hsg.googlegro ups.com
> On Mar 14, 6:40 am, "Folkert Rienstra" <see_reply...@myweb.nl> wrote:
> > <pau...@efn.org> wrote in messagenews:1173866711.145155.278150@y80g2000hsf.g ooglegroups.com
> > > On Mar 13, 3:14 pm, Jax <inva...@no-mail.com> wrote:
> > > > Home user with XP Pro.
> >
> > > > I bought some 160 GB hard drives a couple of years ago and they got
> > > > filled up with data.
> >
> > > > I have now migrated all the data off these 160 GB hard drives and will
> > > > now use the drives to hold backups.
> >
> > > > QUESTION ---> As the HDDs are now empty is it worth writing zeros,
> > > > before using them again, in order to force the HDD to map out any
> > > > defective sectors?
> >
> > > > QUESTION --> Or will mapping out of any defective sectors happen
> > > > automatically when any bad sectors are next written to, which means it
> > > > is not worth writing the zeros?
> >
> > > It's worth zeroing the data on the drives under two circumstances.
> >
> > > 1) You're selling them, and don't want any one to steal your bank
> > > account info, etc.
> >
> > > 2) You don't want anyone to see your porn collection :)
> >
> > > If it has bad sectors, replace the unit. According to a very recent
> > > google study of over 100,000 consumer grade hard drives,
> > > those with read errors were 39 times more likely to fail within
> > > 60 days than those without.
> >
> > Which says absolutely nothing if those without don't fail, now is it.
> >

> Of COURSE drives without bad sectors do fail.

But not all. Without a percentage, 39 times or 16 times is a useless number.

> Otherwise the statement would be different.
>
> > And the exact phrase was:
> > "After the first scan error, drives are 39 times more like-
> > ly to fail within 60 days than drives without scan errors."
> >
> > Unfortunately there is no such thing as a 'scan error'.

> I'd presumed it was a synonym for a bad spot on the drive in question.

Yup, detected by a very particular action of the drive. Problem is,
there is no such attribute with that name. So how will they know.
They particularly isolated them from the pending ('probational')
counts, the online and the offline reallocated counts, so it's not those.

>
> > Your 'read' errors appear under probational counts.
> > "The critical threshold for probational counts is also one:
> > after the first event, drives are 16 times more likely to fail
> > within 60 days than drives with zero probational counts."
> >
> > There were other inconsistencies in the report as well, like lower
> > risk numbers for the total lifetime (longer than 60 days).
> >
> > They also didn't say what they considered a failure and whether the
> > 'failed' drives actually failed in a different system once replaced.
> > Neither did they check whether it was the system killing the drives.
>
> Actually, yes they did specify what they counted as a failure. I'm
> paraphrasing because I don't have the report in front of me. "A drive is
> considered to have failed if it was replaced as part of a repair operation".

But no explanation of what a 'repair operation' is and what prompts it.
A simple single bad block in the wrong place may prompt a 'repair operation'
where the drive is simply replaced as part of a quick fix by lack of other repair
options. That doesn't necessarily mean that the drive itself is beyond repair.

>
> >
> > > It's worth checking the drive for bad sectors.