Re: It seems being in an explosion isn't enough...

2008-05-09 Thread Leichter, Jerry
On Thu, 8 May 2008, Perry E. Metzger wrote:
| Quoting:
| 
|It was one of the most iconic and heart-stopping movie images of
|2003: the Columbia Space Shuttle ignited, burning and crashing to
|earth in fragments.
| 
|Now, amazingly, data from a hard drive recovered from the fragments
|has been used to complete a physics experiment - CXV-2 - that took
|place on the doomed Shuttle mission.
| 
| http://blocksandfiles.com/article/5056
| 
| Now, this article isn't written from a security perspective, but I
| think the implications are pretty obvious: quite a bit can happen to a
| hard drive before the data is no longer readable.
On the other hand ... from a report in Computerworld, we have:

[Jon] Edwards [a senior clean room engineer at Kroll
Ontrack, which did the recovery work] said the
circuit board on the bottom of the drive was burned
almost beyond recognition and that all of its
components had fallen off. Every piece of plastic on
the model ST9385AG hard drive melted, he noted, and
all the electronic chips inside had burned and come
loose.

Edwards said the Seagate hard drive -- which was
about eight years old in 2003 -- featured much
greater fault tolerance and durability than current
hard drives of similar capacity.

Two other hard drives aboard the Columbia were so
severely damaged that it was impossible to extract
any usable data, he added.

-- Jerry

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Re: It seems being in an explosion isn't enough...

2008-05-09 Thread Ali, Saqib
Edwards said the Seagate hard drive -- which was
about eight years old in 2003 -- featured much
greater fault tolerance and durability than current
hard drives of similar capacity.

I am not so sure about this statement. The newer drives are far more
ruggedized and superior in constuction. For e.g. the newer EE25 are
designed to operate @
1) Operating temperatures of –30°C to 85°C
2) Operating altitudes from –1000 feet to 16,400 feet
3) Operating vibration up to 2.0 Gs
4) Long-duration (11 ms) shock capability of 150 Gs

where as the older ST9385AG:
1) Operating temperatures of 5° to 55°C (41° to 131°F)
2) Operating altitudes from –1,000 ft to 10,000 ft (–300 m to 3,000 m)
3) Operating vibration up to 0.5 Gs
4) shock capability of 100 Gs


Source:
http://www.seagate.com/docs/pdf/datasheet/disc/ds_ee25_2.pdf
http://www.seagate.com/support/disc/manuals/ata/9655pma.pdf

saqib
http://doctrina.wordpress.com/

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Re: It seems being in an explosion isn't enough...

2008-05-09 Thread Leichter, Jerry
On Fri, 9 May 2008, Ali, Saqib wrote:
| Edwards said the Seagate hard drive -- which was
| about eight years old in 2003 -- featured much
| greater fault tolerance and durability than current
| hard drives of similar capacity.
| 
| I am not so sure about this statement. The newer drives are far more
| ruggedized and superior in constuction. For e.g. the newer EE25 are
| designed to operate @
| 1) Operating temperatures of ?30?C to 85?C
| 2) Operating altitudes from ?1000 feet to 16,400 feet
| 3) Operating vibration up to 2.0 Gs
| 4) Long-duration (11 ms) shock capability of 150 Gs
| 
| where as the older ST9385AG:
| 1) Operating temperatures of 5? to 55?C (41? to 131?F)
| 2) Operating altitudes from ?1,000 ft to 10,000 ft (?300 m to 3,000 m)
| 3) Operating vibration up to 0.5 Gs
| 4) shock capability of 100 Gs
Well, he's the guy who actually recovers data from the things.

I think the main issue here is that the older drives used much larger
magnetic domains on the disk, inherently providing a great deal of
physical redundancy, for those with the equipment to make use of it.
Also, the encodings were much simpler and the controllers much less
sophisticated.  Today the controller/head/disk are effectively a single
unit, tightly coupled by complex feedback loops.  The controller writes
data that it will be able to read, adjusting things based on what it
actually reads back.  I've been told - I can't verify this - that in
practical terms today, if you lose the controller, the data is toast:
Another nominally identical controller won't be able to read it.

-- Jerry


Re: It seems being in an explosion isn't enough...

2008-05-09 Thread mark seiden-via mac
i think the issue may simply devolve to  lower areal density in the  
old drives.

i.e. the bits are bigger.

does anyone know if they used encodings that were more tolerant of  
certain kinds of errors

in the past which are less common (and so, not worth doing) than now?


On May 9, 2008, at 1:44 PM, Ali, Saqib wrote:


  Edwards said the Seagate hard drive -- which was
  about eight years old in 2003 -- featured much
  greater fault tolerance and durability than current
  hard drives of similar capacity.


I am not so sure about this statement. The newer drives are far more
ruggedized and superior in constuction. For e.g. the newer EE25 are
designed to operate @
1) Operating temperatures of –30°C to 85°C
2) Operating altitudes from –1000 feet to 16,400 feet
3) Operating vibration up to 2.0 Gs
4) Long-duration (11 ms) shock capability of 150 Gs

where as the older ST9385AG:
1) Operating temperatures of 5° to 55°C (41° to 131°F)
2) Operating altitudes from –1,000 ft to 10,000 ft (–300 m to 3,000 m)
3) Operating vibration up to 0.5 Gs
4) shock capability of 100 Gs


Source:
http://www.seagate.com/docs/pdf/datasheet/disc/ds_ee25_2.pdf
http://www.seagate.com/support/disc/manuals/ata/9655pma.pdf

saqib
http://doctrina.wordpress.com/

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