Will freezing your hard drive help recover its data?

Question

^Source

There seems to be (anecdotal) evidence that putting your hard drive in the freezer can make it readable again, at least for a short time:

• Lifehacker - Save a Failed Hard Drive in Your Freezer
• Geeks are Sexy - Freeze your hard drive to recover data: Myth or reality?
• Data Recovery Pros - Freezing Method

I guess that by doing this, some metal parts in the HD could contract, putting back in place defective parts, and making everything work again for a few minutes. [Source]

But data recovery expert Scott Holewinski advises against it in this video (YouTube), saying

... putting your hard drive into the freezer is the WORST thing you could possibly do in your attempt to recover your data as it can actually render your HD completely unrecoverable (due to water condensation)

But people who say it does work usually recommend wrapping the HD in a sealed bag to avoid condensation (see picture above).

My question:
Is the method of freezing your HD for data recovery viable?
Will sealing the HD in a ziploc bag actually help avoid the condensation problem?
(AFAIK there is air inside the HD)

Answer 1

TL;DR: No, it's not a viable method, it will likely cause damage and will not likely work at all.

Here's what the largest data recovery firms say on the matter:

datarecovery.com

Stamped on pretty much every page of the site:

Please keep in mind that hard drives are delicate instruments. Like any other delicate instrument, if they are not handled with care or properly cooled, you may experience a failure. Hard drives are sensitive to heat, rapid temperature changes, static electricity, power surges and physical shock. We estimate that most hard drive failures occur due to operating conditions, not manufacture defects.

Which pretty much means, don't mess around with temperatures because HDs are very sensitive to that.

In fact, according to krollontrack.com, hard drives are so temperature dependent that thermal expansion (and I am adding: thermal contraction) are relevant to the design of the base casting assembly:

Today’s hard drives have no room for errors when it comes to platter and head alignment. The tolerances are so exacting that hard drive manufacturers even design ways to keep the Base-Casting Assembly, where all the components are attached to, from shifting due to high temperature situations. For instance, one hard drive manufacturer of high performance SCSI based drives actually designs their Base-Casting Assembly with pre-stress points. The assembly does not line up from corner to diagonal corner—it’s pre-torqued. When the casting assembly heats up, the unit actually twists back (thermal expansion) into a true line-up from corner to corner.

Unsurprisingly, the correct advice abounds on data recovery sites, for example datarecoverylabs.com:

If a drive is making unusual mechanical noises, turn it off immediately and contact a data recovery specialist.

securedatarecovery.com—boasting high-profile customers, from Nasa to Microsoft—also gives the same advice:

Stopping all use of the damaged equipment or medium is the single most important step in any data loss scenario.
Attempting to perform data recovery on your own is very dangerous - if you are not absolutely sure of what you are doing, you might jeopardize the safety of your data. Do not attempt to use data recovery software, and never try to disassemble the hard drive on your own. Continuing to use your hard drive while it is in a degraded state can endanger your data and make the data recovery process more difficult.

But I think nobody makes it more explicit than datarecovery.net:

• DO NOT put your drive in the freezer and then try to spin it up. It is possible that moisture has condensed on the media surfaces. This WILL cause head contact if it has and will destroy the drive.
• DO NOT listen to your friends or continue to look for home remedies on the net such as the one mentioned above, seek professional help if you value the lost data.

As a side note: not a single one boasts "cryogenic units" or anything similar. All the most reputable ones boast clean rooms and privacy/security standards.

Answer 2

I speak as a professional who has worked as a Data Recovery specialist for a firm that specialised in this.

There are three common types of hard drive failure:

Control Board failure: This is where there is a short or surge that damages the controller board of your hard drive. The symptoms of this are the drive not being found by the BIOS, the drive not "spinning up", sometimes an odor of ozone (if the short is active). Freezing will not fix this failure. Replacing the board usually allows for full recovery of the data. The difficulty is finding a board that works with your exact model of hard drive. If you have one, it's very simple to replace.

Motor Seized: This is the motor that causes the hard drive to spin. It was fairly common in the early hard drives. Parts overheat and expand causing the parts to wedge themselves in a position that doesn't allow the drive to spin freely. Often you could put these in the freezer and it would cause those parts to contract and release allowing the drive to work again. The miniaturization of the motors have reduced the frequency of this failure, and made it so that the damage from them is often irreversible. The data is still on the platter and can be recovered. Symptoms: Drive is recognized by the BIOS But does not spin up. Sometimes you can hear the motor trying to move but it is a constant whine (older drives only). Data recovery places do not want you freezing these for several reasons:

• it is an easy fix, if you know how to fix it and have the time, so they can charge a lot of money and recover all of your data (win win),
• if it is not a motor failure and is other mechanical failure you can cause data corruption(see below)

Head Crash: This is the noticable kerthunk kerthunk kerthunk that anyone who has ever heard it remembers. The drive seems to spin up, thunks 3 or 4 times then spins down - rinse & repeat. Sometimes it will even boot up. This thunk is the drive head making contact with the platter and being propelled away (momentum) every time the head touches the platter it scrambles some of the data on it. The more often the head crashes the more data is destroyed, the less likely to recover what you want. No amount of freezing is going to help here. There is physical damage to the parts that are responsible for reading the data. In order to recover data from this we have to replace the drive heads in a positive flowbench (a poor-man's clean-room) and hope the disk damage does not cause them to crash again. These are generally a bit more interchangable.

Evidence: http://www.dataclinic.co.uk/hard-disk-failures.htm