SpinRite

[Joshua Judson Rosen]

Mike Bilow <mikebw at colossus.bilow.com> writes:
>
> >    SpinRite will read every block on the disk, to make sure they still
> > can be read.  This is useful.  But even CHKDSK/SCANDISK will do that,
> > and have since DOS 6, circa 1993.
>
> As explained, SpinRite went directly to the hardware, which was the only 
> way to bypass ECC. By the way, CHKDSK does not by default read every 
> sector: the "/R" switch is required to enable that behavior, and it 
> certainly could never disable ECC.
>
> >    SpinRite will read-and-rewrite blocks.  There are scenarios where
> > this may be a plausible benefit, such as allowing the drive's built-in
> > relocation mechanism to relocate a marginal sector.  But "badblocks
> > -n" will do the same thing, for free.
>
> SpinRite was not looking for bad blocks, which are easy enough to find, 
> but for "gray area" blocks that were good enough to be readable with ECC 
> enabled but not good enough to be readable with ECC disabled.

But, how do you circumvent the sector-remapping that modern drives do?

(and, if the answer is `you don't', then what is SpinRite actually
 doing that's useful *today*? And haven't some of Gibson's
 `direct manipulation' claims basically decayed into outright lies?)

And what about everything that John Navas included in his critique?

    https://groups.google.com/group/comp.dcom.xdsl/msg/9aeee32323c2978e?dmode=source&hl=en

And...:

> >    To read a bad block, SpinRite will try tricks like seeking to
> > adjacent cylinders/heads/sectors and back again, in various
> > directions.  This was plausible for ancient drives, but everything
> > made in the past 20 years or so has abstracted the real disk geometry
> > away from the host, even when presenting "CHS".  So these tricks are
> > meaningless on anything that isn't old enough to run for congress.
>
> This is largely true, but even so simple an action as explicitly 
> flushing the cache can help. SpinRite was, again, originally intended as 
> a preventative maintenance tool and took off into feature creep where it 
> was marketed as a recovery tool and began to be regarded as a magic 
> panacea. Its underlying theory of operation was certainly plausible and 
> in my opinion correct, but it continued to be sold on its reputation 
> long after it was no longer useful. Even so, in the modern era you are 
> probably better off using something like "smartmontools" to initiate a 
> long self-test on the device.rather than manually test-reading every 
> block on a regular basis.
[...]
> Gibson has a personality, but he walks the walk as well as talks the 
> talk. I've had occasion to ask him very detailed technical questions and 
> he knew his stuff. Gibson's claim about interfacing directly to hardware 
> with register-level awareness was absolutely true in the days of 
> proprietary controllers
[...]
> Yes, SpinRite was misunderstood and overhyped, and it stuck around as a 
> magic elixir for far longer than it should have, but 25 years ago it was 
> a remarkably effective and prescient utilization of stone knives and 
> bear skins.

In other words..., Gibson *used to* appear to know what he was talking
about, and SpinRite *was* actually not-a-scam 25 years ago, but you guys
agree that *today* it's pure snake oil?

-- 
"Don't be afraid to ask (λf.((λx.xx) (λr.f(rr))))."