Freezing a HDD

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
--
Please remove one 'i' from my address when replying by email.

On Sun, 30 Oct 2011 14:06:09 +1100, Franc Zabkar
wrote:

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

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
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. 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.

Franc Zabkar wrote:
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
--
Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email:
GnuPG: ID: 1E25338F FP: 0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F
----
Cuddly UI's are the manifestation of wishful thinking. -- Dylan Evans

Gerald Abrahamson wrote
Franc Zabkar wrote

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.

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.

On 30 Oct 2011 14:44:37 GMT, Arno put finger to
keyboard and composed:

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
--
Please remove one 'i' from my address when replying by email.

Franc Zabkar wrote:
On 30 Oct 2011 14:44:37 GMT, Arno put finger to
keyboard and composed:

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.

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
--
Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email:
GnuPG: ID: 1E25338F FP: 0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F
----
Cuddly UI's are the manifestation of wishful thinking. -- Dylan Evans

Arno wrote:
Franc Zabkar wrote:
On 30 Oct 2011 14:44:37 GMT, Arno put finger to
keyboard and composed:

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.

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 ?

On Mon, 31 Oct 2011 07:56:21 +1100, "Rod Speed"
wrote:

Gerald Abrahamson wrote
Franc Zabkar wrote

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.

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.

Udder BS. Freight in planes, trucks, ships, and cars (etc)
gets frozen all the time when the temps are low enough. That
is why they have heated trucks, heated containers, etc--for
transporting cold-sensitive items. HDDs ship via UPS
ground--NON-heated trucks (OTR--not just local delivery).

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.

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.

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.

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

Gerald Abrahamson wrote
Rod Speed wrote
Gerald Abrahamson wrote
Franc Zabkar wrote

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.

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.

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.

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.

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.

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.

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.

Gerald Abrahamson wrote:
On Mon, 31 Oct 2011 07:56:21 +1100, "Rod Speed"
[...]
It isnt the cold air that does that, its the cold surfaces
that condense the moisture in that cold saturated air.

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
--
Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email:
GnuPG: ID: 1E25338F FP: 0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F
----
Cuddly UI's are the manifestation of wishful thinking. -- Dylan Evans