<br><br><div class="gmail_quote">On Fri, Jan 27, 2012 at 6:06 PM, Michael H. Warfield <span dir="ltr"><<a href="mailto:mhw@wittsend.com">mhw@wittsend.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div class="im">On Fri, 2012-01-27 at 16:38 -0500, Wolf Halton wrote:<br>
> I am not going down to bit-level analysis, but plug them in and both the<br>
> gnome disk utility and windows' similar app tell me that the disks are<br>
> unformatted.<br>
<br>
</div>Fine. They're unformatted. Format the buggers.<br>
<br>
Seriously... They COULD NOT have been damaged by metal detectors or any<br>
other magnetic influence (other than being hooked up to a computer) and<br>
even operate.<br>
<br>
Warning... Extreme low level details to follow...<br>
<br>
Old OLD drives use to have stepper motors and the tracking was very<br>
course. You could wipe out every bit on every platter and recover that<br>
drive because the tracking was determined by the increments of the<br>
motor. Slightly more modern variations use actuators with various<br>
sensors. But we're talking in the few Meg range here.<br>
<br>
Later drives dedicated an entire platter surface as a "servo surface"<br>
and the heads where driven by magnetic solenoid actuators that took quad<br>
phase signaling from the servo platter to control where the trackers<br>
where. THIS is the era of Steve Gibson and SpinRite. Drives would age<br>
and the actuator arms would flex and change in time and tracks would get<br>
out of alignment and start showing errors because they now longer<br>
aligned with the server platter. SpinRite could correct this by<br>
rewriting the tracks and they would once again be in alignment (they're<br>
aligned to where the are written last). If a track on a data platter<br>
was lost, you lost data. If a track on the servo platter was lost, you<br>
lost that entire cylinder and several cylinders near-by. If a magnetic<br>
field could destroy a data track, it could destroy the servo platter and<br>
the drive it toast. There was a "low level format" for those drives but<br>
you STILL needed the servo platter. There were in the hundreds of Megs<br>
to a few Gig for some very expensive models.<br>
<br>
That's ancient technology. Modern drives (last 15 years or so) embed<br>
the servo data in the gaps between the sectors. There is no "servo<br>
platter" (and 90% of the value of SpinRite is now BullShit) and the<br>
drive actuator system aligns itself through a feedback mechanism each<br>
time a gap passes underneath it. You may rewrite sectors but the<br>
sectors are aligned not to a servo platter but to the quad phase signals<br>
in the gaps before and after the sector. So they CAN NOT DRIFT like the<br>
old drives. But, again, if something destroys that signaling, you can<br>
not format it, the drive is simply toast and will throw errors and<br>
simply fail to initialize.<br>
<br>
In modern day lingo, formatting is purely high level. If the drive<br>
works at all without giving errors, then the tracking and sync patterns<br>
and true "low level" formatting are present and invisible to you and<br>
nothing in shipping can damage the high level formatting without<br>
destroying the low level formatting without breaking the box open and<br>
hooking it up to something.<br>
<br>
It just wasn't formatted. No big deal. Could you format it? Could you<br>
partition it?<br>
<br>
Mike<br>
<div class="HOEnZb"><div class="h5"><br></div></div></blockquote><div>So if the drives were degaussed, they wouldn't even have shown up as "Unformatted Disc" when plugged into a computer. I didn't do the next step, and attempt to format the drives. I just sent them back to the shipper. They were the ones who said they had put the data on the discs. <br>
Thanks for the very detailed explanation.<br><br>Wolf<br></div><blockquote class="gmail_quote" style="margin:0pt 0pt 0pt 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div class="HOEnZb"><div class="h5">
> On Fri, Jan 27, 2012 at 3:32 PM, Michael Trausch <<a href="mailto:mike@trausch.us">mike@trausch.us</a>> wrote:<br>
><br>
> > By "entirely unformatted" I presume the disk is full of zeroes? If that is<br>
> > the case, the shipper most likely made a mistake...<br>
> ><br>
> > --<br>
> > Sent from my CyanogenMod mobile device.<br>
> > Please excuse any typos.<br>
> > On Jan 27, 2012 3:01 PM, "Wolf Halton" <<a href="mailto:wolf.halton@gmail.com">wolf.halton@gmail.com</a>> wrote:<br>
> ><br>
> >> I have 4 hard drives sent to me. One of the 4 is entirely unformatted<br>
> >> while the other three are formatted (and full of data).<br>
> >> Is there any way that a metal detector or some-such DHS TSA device could<br>
> >> entirely clear 1 of 4 discs??<br>
> >><br>
> >> The sender said there was data on all the disks when they were packaged<br>
> >> up.<br>
> >><br>
> >> --<br>
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</div></div><span class="HOEnZb"><font color="#888888">Michael H. Warfield (AI4NB) | <a href="tel:%28770%29%20985-6132" value="+17709856132">(770) 985-6132</a> | mhw@WittsEnd.com<br>
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