How To Ruin Your Chances Of Data Recovery

No Chance Data Recovery

Maybe the title is a bit harsh, but in the past week I have seen an unusually high number of hard drives ruined by avoidable problems. There is nothing more frustrating than knowing the data would have been recoverable if  the hard drive hadn’t been tampered with first.

Manufacturing

Hard drives are manufactured in a controlled environment. Staff wearing white overalls,  gloves, and masks, control machines which are carefully organised to prevent contamination getting inside the hard drive.

Clean Room

To prevent contamination when repairing the inside of a hard drive, it is necessary to use a cleanroom. This is a specially designed system that filters the air and keeps airborne particles to a minimum. A cleanroom is the only safe way to open a hard drive. We have one of these, which allows us to carry out the most intricate repairs without any risk of particle damage.

Damage

Before opening a hard drive for internal rework, it is crucial to confirm that there is an internal mechanical problem in the first place. For instance, our data recovery process has numerous tests we can carry out before we confirm that the problem is under the hood. Only then will we open the top cover and check for damage inside. Unlike CDs or DVDs, the internal disks of a hard drive are not designed to come into contact with normal air. Even a fingerprint could mean the difference between a successful or unsuccessful recovery. If you slip with a screwdriver then forget it.

The numbers

On a percentage basis of all the failed drives we receive (hundreds per year), we only need to go to the cleanroom with around 10%. There are likely to be far less intrusive ways into the data without ever taking off the top cover.

Even if…

I’ve lost count of the number of times I’ve been told, “It’s an internal fault. The heads are clicking.” Although some drives will click as a symptom of failed heads, there are so many other reasons to cause a drive to click that it is not a reliable way to diagnose problems.

Reasons a hard drive will click

  • Electronic fault
  • Firmware fault
  • Bad sectors
  •  Weak (but not completely failed) heads
  • Problems reading partition info

All of the problems above can be overcome without ever unscrewing the top cover. In fact, removing the top cover will only introduce more doubt to the diagnosis. If the top cover is removed outside of a cleanroom, then not only do the above problems need to be solved, but also new problems of contamination and possibly damage by tools.

(Don’t) Get the discs out

Another common wrong diagnosis is to take the disc pack from one drive and place it into a donor drive. Although this is a correct course of action for some drives, there are some serious implications. First, when the disc pack is built it is clamped together onto the spindle motor. This alignment is so crucial that if you remove one disc at a time, you will never be able to regain this alignment. This was true 20 years ago when the magnetic data was nowhere near as densely packed. Rotate the discs a fraction of a millimetre and you can wave goodbye to all the files.

It is also the case that most of the hard drive firmware is now stored on the discs, so moving them to a new donor will not help if the fault is firmware based.

Advice

If you are even considering a destructive course of action, at least get some professional advice first. You don’t need to follow the advice, but at least it gives somebody (maybe me) the option to give a warning. You don’t want to find out later that the data would have been simple to recover, if only…

Maxtor DiamondMax Clockwise Discs

You have heard of the myth about water behaving differently from the northern hemisphere compared to the southern hemisphere. Especially when draining water out of a sink or bath. Well apparently this is a myth and not fact.

So what has this got to do with hard drives? Well the same was said about some of the old Maxtor hard drives and why they were built with clockwise disc rotation. Where they built for the southern hemisphere market and do they work as well in the northern hemisphere. Built in mid 2000 the Maxtor DiamondMax 10 hard drives were designed to spin in the opposite direction to the conventional mechanical hard drives.

I could not find any information as to why they were built this way and whether this design did improve performance depending on location in the world. Maybe this question will never be answered.

See pictures below of a the internal working of a conventional hard drive compared to the Maxtor DiamondMax 10 hard drives.

Conventional WD Hard Drive

Conventional Anti Clockwise Disc
Conventional Anti Clockwise Disc

Maxtor DiamondMax Hard Drive

Maxtor DiamondMax Clockwise Discs
Maxtor DiamondMax Clockwise Discs

Common Data Recovery Myths Exposed

Myth 1: When files are deleted they are gone forever.

Fact: When files are deleted they are actually only removed from an index. Unless you then overwrite those sectors with new data, the files will still be there. If you delete a file it is important to stop using the computer. Even browsing the internet causes cache files and images to be downloaded to the hard drive, potentially overwriting the deleted files.

Myth 2: Putting a hard drive in the freezer will bring it back to life.

Fact: This is an old one, which will not die. We have never had to put a hard drive in a freezer. There is only anecdotal evidence that freezing a hard drive helps in any way. One of the most common types of hard drive failure is firmware corruption, which cannot be fixed in a freezer. I would be worried about introducing condensation into the drive, which could be devastating. If anyone knows where this idea came from, or how the freezer is supposed to help, then I would love to hear about it.

Myth 3: The FBI can recover anything.

Fact: The FBI are bound by the same laws of physics as we are. If a hard drive has had a head crash, and scraped the magnetic coating off the platter, there is no data left to recover. You cannot read magnetic data from particles of dust! Even the FBI can’t recover that.

Myth 4: The best way to recover a hard drive is by swapping the platters out.

Fact: In almost all cases, you should not disturb the alignment of the platters. They are manufactured within strict tolerances which cannot be recreated outside of a manufacturing environment. If the problem lies with the on-disk firmware, electronic components, or read / write heads, then swapping the platters would not solve anything.

Note – If the spindle motor gets stuck then it can be necessary to swap the platters, but only as a last resort.