Freezing a HDD

[Franc Zabkar]

There is a current thread at HDD Guru which is discussing whether
freezing a HDD causes platter damage:
http://forum.hddguru.com/viewtopic.php?f=3&t=20957

Can anyone offer any insight, particularly in regard to the vague
throwaway statement by "Doomer" in respect of "firmware and data
density"? My BS alert went off, but I couldn't pin it down.

- Franc Zabkar

 

[Arno]

There is a current thread at HDD Guru which is discussing whether
freezing a HDD causes platter damage:
http://forum.hddguru.com/viewtopic.php?f=3&t=20957

Can anyone offer any insight, particularly in regard to the vague
throwaway statement by "Doomer" in respect of "firmware and data
density"? My BS alert went off, but I couldn't pin it down.

Magnetization is not negatively affected by low temperatures.
It is by high temperatures. Sounds like complete BS to me.

As to why no (reliable) operation below 40C, there is a number
of reasons:

- Electronics will shift its parameters too far.
- Lubricants will change their behaviour too far
- Components may be damaged due to mechanical (thermal) stress
- The cold air may change behaviour too far
- The heating up process in operation may damage things

Firmware and data-density is utter and complete BS though.


Of course HDDs are suceptible to moisture and condensation.
That is why you need to pack it airtight when putting it in.
The thing here is that a HDD also has a maximu rate of temperature
change and a freezer routinely exceeds that. This may overload
the air-filter. But other than that, I don't see any way a
conventional freezer (-18C) could do damage to the platters.

Incidentally, If I understand this right, the freezing in
this case was not to do immediate data recovery afterwards,
but the drive was declared "fixed". This is of course BS.
Freezing can give you a chance to get a drive up and running
that refuses to start otherwise. It can give you a few minutes
of reliable operarion for a drive that does not work
reliably anymore. The thoery is that shifting operation
parameters cause a shift to "works better" or "works worse"
and most electronics works better when cold.

Freezing cannot magically fix anything permanently. It
temporary shifts operation parameters and sometimes
this gives you a few minutes for immediate data recovery.
Nothing more.

Arno

 

[Rod Speed]

Gerald Abrahamson wrote

When not operating, the drive heads are parked off the
data areas of the platters. If the the drives are off and the
heads are anywhere else, then the drive has failed.... Thus,
transporting drives via air freight works because the drives
do get exposed to those low temps for extended time periods

No they dont. Freight doesnt freeze.

and they do survive just fine.

The operational temp range of a drive is also based on its
design and materials. Once a drive is running, it creates
its own "heat island" (so to speak) due to its electronics
and the motor generating heat. The real issue is *internal*
vs *external* air. The *running* drive generates heat--and
the internal air is warmed and does not "exchange" much
with external air--there is just the breather hole to allow for
air pressure changes (hence the need to *cool* drives in
boxes). Running drives in a cold environment will tend to
stay dry because the cold dry air around them will absorb
and *hold* available moisture rather than deposit it on a
warmer surface.

It isnt the cold air that does that, its the cold surfaces
that condense the moisture in that cold saturated air.

Hence the minimal snowfall at either pole--the ability to
*create* snow (condensation) requires warmer/moister
air to meet a colder temp to cause condensation to occur.
The drives are *warmer* than the cold air around them
when they are operational, so it is a contradiction in terms
to worry about condensation in *cold* operational environments.

But not when the drive is put in the freezer not running.

 

[Franc Zabkar]

Firmware and data-density is utter and complete BS though.

That's what I suspect. However, my understanding is that "Doomer" is a
data recovery professional who is employed by Seagate in this
capacity. Therefore I would think that he would have access to
Seagate's internal technical documentation. He is also well respected
by his peers.

- Franc Zabkar

 

[Arno]

On 30 Oct 2011 14:44:37 GMT, Arno <[email protected]> put finger to
keyboard and composed:

That's what I suspect. However, my understanding is that "Doomer" is a
data recovery professional who is employed by Seagate in this
capacity. Therefore I would think that he would have access to
Seagate's internal technical documentation. He is also well respected
by his peers.

But this is outside of what he does. For data recovery, he will not
go below -40C or the like. The only possible connection with firmware
is that modern HDDs regulate head-hight thermally and there will be
some table in the firmware that adjusts this to ambient temperature, at
least directly after start-up. It is quite possible this works only
down to -40C. But that would not be cause, but effect. Because other
things fail below -40C anyways, there is no need to have working
head-hight regulation below -40C.

As to data-density, I do not see any connection at all, except
something even more artificially constructed.

My guess would be that this person has not reacted to well too the
respect he is getting and is getting arrogant and sloppy, at least
in some statements outside his core competency.

Arno

 

[8732]

But this is outside of what he does. For data recovery, he will not
go below -40C or the like. The only possible connection with firmware
is that modern HDDs regulate head-hight thermally and there will be
some table in the firmware that adjusts this to ambient temperature,
at least directly after start-up. It is quite possible this works only
down to -40C. But that would not be cause, but effect. Because other
things fail below -40C anyways, there is no need to have working
head-hight regulation below -40C.

As to data-density, I do not see any connection at all, except
something even more artificially constructed.

My guess would be that this person has not reacted to well too the
respect he is getting and is getting arrogant and sloppy, at least
in some statements outside his core competency.

Arno

Just like with you and Win, eh ?

 

[Rod Speed]

Gerald Abrahamson wrote

Udder BS.

We'll see...

Freight in planes, trucks, ships, and cars (etc) gets
frozen all the time when the temps are low enough.

Not with aircraft freight. If it did, the pets in pet containers would die.

That is why they have heated trucks, heated containers,
etc--for transporting cold-sensitive items.

The pets carried as freight in aircraft arent in heated containers.

HDDs ship via UPS ground--NON-heated trucks
(OTR--not just local delivery).

And the contents of those trucks dont freeze.

More BS.

We'll see...

In transit, drives are essentially sealed.

Pigs arse they are. They all have an air vent and what they get shipped isnt sealed.

So the only way they get condensation inside the package is
through failed packaging or improper preparation at the factory.

The packaging isnt airtight.

If put in dry and with minimal reasonably-dry air in a SEALED bag,

Taint in a SEALED bag in the sense that its airtight.

then it makes no real difference. I expect you bundle
your drives with your freshly water-filled ice cube
tray to keep everything "fresh" while they both freeze.

You'll end up completely blind if you dont watch out, boy.

 

[Arno]

More BS. In transit, drives are essentially sealed. So the
only way they get condensation inside the package is through
failed packaging or improper preparation at the factory.

Sealed, often with a moisture-eater inside. The small
"silica gel" bags with the large "DO NOT EAT" are moisture
eaters. Also not that the drives have a filter that
keeps moisture out when the temperature and air pressure
does not change too fast. Drive manuals lists maximum rates
for both.

Arno

 

[Rod Speed]

Gerald Abrahamson wrote

Since when do pets fly in *cargo* planes?

Since as long as we have had planes.

Try again.

No need.

I have received many shipments where
the liquid contents were frozen solid.

Most havent.

Broken bottles as a result in some cases--from various carriers, including UPS.

How odd that retaillers manage to ship beer and water around so effortlessly.

Now, you were saying WHAT about "the contents of those trucks dont freeze"?

Not often enough to matter obviously.

Well, you would know.

Yep, I buy quite a few drives and not one has
ever showed up in a sealed container, EVER.

Drives are individually sealed--each in a plastic bag.

None of mine have been for more than a decade now.

OOPS !!!

Your sig is sposed to be last with a line with just -- on it in front of it, child.

If you ever got a NEW drive, you would know that fact.

Got one just last week thanks.

Yet it works for millions and millions of hard drives per DAY.

Because it doesnt need to be airtight.

Their manufacturing and shipping processes seem pretty "airtight"

Then you need to get your seems machinery seen to, BAD.

given their low failure rate.

Thats because they are designed so that they dont need to be airtight.

Thats why the drive has a vent that usually has a label on it telling you to not cover that.

Close enough so the mfr isn't worried about it.

Because it doesnt need to be airtight.

Thus speaks firsthand experience

Yep, watch plenty of you silly little children end up completely blind.

You've been warned, boy.

 

[Rod Speed]

Gerald Abrahamson wrote

Yeah, I know about the gel packs also. That is to absorb the
bit of moisture/etc that is in the box/bag when packaged.

Mindlessly silly. It would be a lot cheaper to fill it with dry nitrogen, child.

They even do that with car tires now.

I am aware of the Mits RP stuff used by Sony--way
more aggressive than the silica gel ever could be.

And much more expensive than dry nitrogen, child.

 

[GMAN]

Since when do pets fly in *cargo* planes?


Try again. I have received many shipments where the liquid
contents were frozen solid. Broken bottles as a result in
some cases--from various carriers, including UPS. Now, you
were saying WHAT about "the contents of those trucks dont
freeze"?

I believe this. At 40,000 feet its quite easy for a package to freeze on the
airplane and still be frozen at delivery time from the UPS truck.

 

[Rod Speed]

GMAN wrote

I believe this.

More fool you.

At 40,000 feet its quite easy for a package to freeze on the
airplane and still be frozen at delivery time from the UPS truck.

Have fun explaining why the pets dont end up as little frozen corpses,
or why you dont end up with frozen suitcases when you fly anywhere.

 

[Rod Speed]

Gerald Abrahamson wrote

Now we clearly see your lack of knowledge of science and technolory.

This is from the clown that hasnt even noticed that you dont EVER end
up with frozen suitcases when getting your bags after a plane flight.

Pure nitrogen would tend to migrate *through* the bag wall

Have fun explaining why it doesnt with care tires which are indeed filled with that.

---leaving a partial vacuum inside the bag,

Mindlessly silly. Even if the nitrogen did migrate thru
the bag, and it doesnt any more than air which is mostly
nitrogen does, the bag would just collapse, child.

which would then *increase* the likelihood of contamination
of the drive through outside air, dirt, and water being forced
*into* the bag around the drive via air pressure equalization
as the pure nitrogen left the bag.

Thanks for that completely superfluous proof that you have
never ever had a ****ing clue about even the most basic physics.

Not only wont the nitrogen migrate any more than it
does with air which is mostly nitrogen, there wont be
any vacuum, because the bag will just deflate at most.

The drive mfrs are far smarter than you are--and it shows.

Everyone understands basic physics much better than you do, child.

Rubber and chemicals in tires are specifically designed
to hold in air/pressure (35 psi or so)--not so with the
thin plastic bag material used to protect hard drives.

Pity that the air otherwise used is mostly nitrogen, child.

 

[Rod Speed]

Gerald Abrahamson wrote

Because pets generally fly in compartments heated to
40F or so AND those compartments are pressurized.

True of all freight, child. Thats why you dont end
up with frozen bags when you get off a plane flight.

And even dedicated freight aircraft are the same aircraft used for
carrying passengers, with the freight where the passengers usually
are, so that freight is STILL carried where its pressurised and where
it doesnt freeze any more than the passengers ever end up frozen.

Pets do NOT survive when exposed to 30k ft temp/pressures for hours.

Which is why ALL freight is carried in pressurised areas, child.

More of your idiocy exposed.

Nope, yours.

Suitcases, etc do NOT need heated/pressurized compartments--and
I have gotten COLD luggage at baggage claim when on plane flights.

But never FROZEN bags, child.

 

[GMAN]

Because pets generally fly in compartments heated to 40F or
so AND those compartments are pressurized. Pets do NOT
survive when exposed to 30k ft temp/pressures for hours.
More of your idiocy exposed. Suitcases, etc do NOT need
heated/pressurized compartments--and I have gotten COLD
luggage at baggage claim when on plane flights.

Same here. When arriving back from a trip we took to Orlando to visit
Disneyworld, when we got our packages in Salt Lake City and went home, my
wifes handlotion was extremely cold and so was my cologne. The only way
possible that this happened in the middle of July was the approx 40,000
elevation and no pressurized baggage area.

 

[Rod Speed]

GMAN wrote

Same here. When arriving back from a trip we took to Orlando to visit
Disneyworld, when we got our packages in Salt Lake City and went
home, my wifes handlotion was extremely cold and so was my cologne.

But they werent FROZEN SOLID.

The only way possible that this happened in the middle of July was
the approx 40,000 elevation and no pressurized baggage area.

If where they were wasnt pressurized, any liquid
would have erupted all over the contents of the bags.

NOTHING is carried non pressurized areas, even with dedicated
cargo aircraft which has the freight where the passengers would
normally be. They are just conventional aircraft without seats, there
is no way to have the cockpit pressurised and not the main cabin.

You two dont have a ****ing clue about how that sort of aicraft operates.

 

[Rod Speed]

Gerald Abrahamson wrote

So how do packaged bottles freeze and break in transit?

They dont.

Still waiting for you to answer that one....

Nothing to answer because they dont. If they did, we'd see hordes
with broken containers during the customs inspection done with all
international flights checking for drug imports and we dont.

We'd also not see every international airport flogging duty free liquor
to travellers, and we do anyway.

We'd also see all animals arrive dead, and we dont.

You havent got a ****ing clue about the basics.

Now we see you publicly demonstrating how little you
actually know about anything--especially physics.

Are you seriously trying to claim that air isnt mostly nitrogen, child ?
http://en.wikipedia.org/wiki/Air#Composition

Obviously, *you* do not.

Pity about
http://en.wikipedia.org/wiki/Air#Composition

I worked for a major developer of SAI and they
employed mostly...physicists. Doing the basic
research to develop products (machines) used by a
wide range of military, commercial, and R&D businesses.

Waffle as far as
http://en.wikipedia.org/wiki/Air#Composition
is concerned.

And you clearly werent one of them.

My responsibility was to understand what they (the physicists)
wanted so the machines ran and did what they designed it to do.

More meaningless waffle.

The *typical* machine did its work at about 10^-9 to
10^-10 Torr. I started in the division that designed
and built the vacuum pumps--so *I* have a clue.

You clearly dont with the composition of air
http://en.wikipedia.org/wiki/Air#Composition

Then I moved on to Systems--as they loved the fact I save
the business a lot of money by knowing what I was doing.

Easy to claim, child.

The problems they had encountered were disappearing
due to the revised systems I put in place.

Easy to claim, child.

As a lot of the work was done in *clean rooms* (anywhere from
Class 10k to Class 100), *I* can reasonably state I "have a clue".

You clearly dont on the the composition of air, child
http://en.wikipedia.org/wiki/Air#Composition

Not because I say so, but because the creation of that
high-end vacuum *required* an understanding of physics
and knowing how to keep things *clean* of contaminants.

You cant even understand the basics like
http://en.wikipedia.org/wiki/Air#Composition

We had BOTH *chemical* AND *vacuum furnace* (high
heat + gas/vacuum) cleaning, and they were used a lot.

Irrelevant to
http://en.wikipedia.org/wiki/Air#Composition

They did most of it "in house" while I was there. And,
to top it off, they had TWO liquid nitrogen storage tanks
(each about 30' tall) that were refilled by tanker truck as
needed (remote monitoring of tanks via the supplier).

Irrelevant to
http://en.wikipedia.org/wiki/Air#Composition

So, yes, I sorta think I got a clue about gases, vacuums, etc.

You clearly dont on what air is about
http://en.wikipedia.org/wiki/Air#Composition

That was the nature of that entire business.

Must be why you got the bums rush, right out the door onto your lard arse, child.

http://www.airliners.net/aviation-forums/tech_ops/read.main/277700
Read it and weep, child.

A Jap would at least have the decency to disembowel itself, child.
Dont make a mess of the carpet...

 

[Arno]

On Fri, 4 Nov 2011 06:05:06 +1100, "Rod Speed"

ROFLMAO !!!!

Facts are one of those things you just do not like to
admit....

84 proof booze freezes at about -34C. So not a problem for
most flights or ground transportation systems.

There is also the fact that water needs a lot of energy
removed in order to freeze. If there is a layer of
insulation around it, not even a transcontinental
flight might be enough to remove that. Also note that
airplane holds are actually heated. This may lead to
different temperatures, depending on location, (explains
the cold luggage), but it is not the -55C outside.

Reference:
http://toolkit.bootsnall.com/transp...eral-maintenance/pet-treatment-on-planes.html

[...]

I am having trouble verifying your "innert atmosphere
(i.e. nitrogen) diffuses out of sealed plasic bag" claim.

Is this a very slow process? Does it depend on the bag
material? N is actually N2 in air and O is O2, and it seems
to me they are actually pretty close in size and outer
electron configuration (may have that wrong my chemistry
is weak), so something letting N2 trough should typically
also let O2 through?

I also understand that diffusion is sort of a mixing process,
where the mixtures on both sides oft he membrane eventually
equal out (for everything that can get though the membrane
that is).

Got a reference?

Arno

 

[Rod Speed]

Gerald Abrahamson wrote

ROFLMAO !!!!

Juvenile antics on the floor cut no mustard around here, child.

Facts are one of those things you just do not like to admit....

http://cocktails.about.com/od/mixology/f/alcohol_freeze.htm

Pity about the wine and beer which freezes at
only marginally lower temps than water, fool.

Never had any of those freeze in my baggage either.

84 proof booze freezes at about -34C. So not a problem
for most flights or ground transportation systems.

Pity about the wine and beer, child.

You keep arriving brain dead every time....

Wota stunning line in rational argument you have there, child.

What a fricking moron. Doesn't even understand *basic* laws
of physics and chemistry--and he publicly posts that fact
over and over and over again.

Wota stunning line in rational argument you have there, child.

Nice link that proves my point--

Everyone can see for themselves that you are lying again, child.

but *you* totally missed it *AGAIN*. Physics. Chemistry.
With normal air in the bag, the gain/loss *ratio* (through
the bag wall) will be the about the same--so no essential
change in the air composition of the bag contents over time.
On the other hand (ROFLMAO!!), when you put in PURE
nitrogen, the bag will LOSE a lot nitrogen that will NOT be
replaced--which will cause a partial vacuum in the bag.

Why would it be replaced when the bag is filled with
air, but not when its filled with dry nitrogen, child ?

Have fun explaining the physics of that, child.

That partial vacuum will cause the bag
to draw in air from another source--

Another howler. The bag just collapses, child.

Even you should have noticed that balloons do that, child.

air that is contaminated and will cause long-term damage to drives.

Have fun explaining how they work fine when removed
from the bag and installed in a PC, or housing, child.

Thanks for that completely superfluous proof that you
have never ever had a ****ing clue about anything at
all, and why you got the bums rush from that operation
you lied about being the savior of, child.

Its completely trivial to prove that dry nitrogen in
a plastic bag stays the way it always was and
doesnt end up with a vacuum in the bag, child.

And that might just explain why cameras and binoculars
etc are routinely filled with dry nitrogen to stop them
fogging up internally in very cold conditions, child.

<reams of your lies flushed where they belong>

 

[Rod Speed]

David Brown wrote

Arno wrote

Thats obvious.

Yep.

There is none on that howler.

I don't know much about this stuff,

Thats obvious.

and I am not going to "take sides" as to who is right and what really happens. But I think the concept here is
partial gas pressures and diffusion.
Nope.

If you have a bag filled with N2 and normal air pressure, in a normal air atmosphere, and the bag is not completely
gas tight, then as far as the N2 is concerned it is actually at a higher pressure than the N2 outside the bag.

Utterly mangled.

So the N2 will try to leak out until it is at 78% atmospheric pressure.

That doesnt happen even if the nitrogen does diffuse out at a
higher rate than air in the bag does, because even you should
be able to grasp that the bag just collapses as the nitrogen diffuses
out and so you get no reduction in pressure inside the bag.

And you havent explained why the nitrogen would diffuse out of the
bag any faster than nitrogen in a bag filled with air would anyway.

Depending on the type of bag, the way its arranged, etc., it will either crumple a bit and stay at lower total
pressure,

So it wont get to 78% atmospheric pressure.

or it O2 (and traces of CO2, Ar, H2O, etc.) will leak in to match normal air mixture.

Why should it 'leak' in when the pressure inside the
bag has to be the same as the pressure outside it ?

If you fill the bag with hydrogen instead, that does diffuse out of
the bag faster than air would, just because its smaller molecules.
But all that does is see the bag eventually deflate and you can
see that happening with balloons filled with hydrogen or helium.

How fast this might go, I can't say anything about. And I also can't
say whether the bag will simply crumple due to the lower pressure,

Corse it does and even you should be able to say that.

or whether the O2 will diffuse in.

Corse it doesnt at any different rate than the nitrogen outside the bag does.

But maybe it will give you some idea of what might be happening.

Nope, you just mangled the physics utterly.