Since we're on the topic of extreme environments, I could add a bit I
Googled up about altitude. I recalled reading an article of these
satellite tech guys that were up in the Himalyas with their laptops, and
they reported being able to hear the heads of the harddrives
"screeching" away because there wasn't a proper cushion of air between
the head and the disk platter. They didn't sound too worried about it,
but the following indicates that you might have reason to worry about
10,000 feet:
(from http://linuxreviews.org/dictionary/Hard_drive/)
> The (mostly) sealed enclosure protects the drive internals from dust, con=
densation, and other sources of contamination. The hard disk's read-write h=
eads fly on an air bearing (a cushion of air) only nanometres above the dis=
k surface. The disk surface and the drive's internal environment must there=
fore be kept immaculately clean to prevent damage from fingerprints, Shair,=
dust, smoke particles, etc. given the submicroscopic gap between the heads=
and disk.
> Contrary to popular belief, a hard disk drive does not contain a vacuum. =
Instead, the system relies on air pressure inside the drive to support the =
heads at their proper flying height while the disk is in motion. Another co=
mmon misconception is that a hard drive is totally sealed. A hard disk driv=
e requires a certain range of air pressures in order to operate properly. I=
f the air pressure is too low, the air will not exert enough force on the f=
lying head, the head will not be at the proper Sheight, and there is a risk=
of head crashes and data loss. (Specially manufactured sealed and pressuri=
zed drives are needed for reliable high-altitude operation, above about 10,=
000 feet. This does not apply to pressurized enclosures, like an airplane c=
abin.) Modern drives include temperature sensors and adjust their operation=
to the operating environment.
best,
derek
--
derek holzer ::: http://www.umatic.nl
---Oblique Strategy # 176:
"What context would look right?"
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