Crash and burn - physical media damage

Can physical media damage mean total data loss?

Kroll Ontrack unravels the mystery behind physical media damage in hard drives.

Today’s modern clean room is a really exciting place to work; engineers see all kinds of drives, in all shapes and sizes. Despite this constantly changing environment, there is one thing that they see on a day-to-day basis that causes endless headaches and can occasionally mean a job is unrecoverable - welcome to the world of Physical Media Damage!

What is Physical Media Damage (PMD)?

PMD can be described as: damage caused when the magnetic coating on the platters is disturbed or destroyed.

What causes Physical Media Damage?

PMD most commonly occurs when the read/write heads come in to contact with the spinning platters. This my be as a result of the drive being knocked or dropped while it is in operation. Over-use and overheating can also be contributing factors.
Platters can also be damaged if the internal chamber becomes contaminated. Any substance that infiltrates the hard drive case can potentially cause a crash if it settles between the heads and the platter.

Another common cause of PMD is carelessness when opening the drive. Many of our customers open the drives before they send them to us, even the slightest scratch or small dent in the platter can sometimes render a drive unrecoverable. This is why Kroll Ontrack always advises customers not to open the drives (or indeed any media) prior to sending it an expert.

If a drive crashes is it still recoverable?

This is a question Clean Room engineers are asked all the time. The answer - albeit a slightly unhelpful one - is “that it depends on the make of the drive, and the severity of the crash”.

The best way to look at this is to try and understand different types of crashes. At Kroll Ontrack, we split the severity of the damage in to three main categories:

• Crash Level 1 (C1)
  Most of the time these are very minor crashes that can barely be seen with the naked eye.
  However, if these crashes lie within the system area then it may prevent the drive from coming ready and being accessible. This means that occasionally a C1 can still be unrecoverable.
• Crash Level 2 (C2)
  A C2 crash is immediately visible, and depending on the drive it can be unrecoverable. However, it is still possible to image drives even when the damage is extensive.
• Crash Level 3 (C3)
  This is the end of the road as far as data recovery is concerned. A C3-level crash means all the magnetic coating has been scratched off the platters. Hence, there is no more data present so the drive is unrecoverable.

Can PMD affect any other storage media?

PMD can occur in any storage device which has mechanical moving parts. Our engineers see PMD in CD’s, DVD’s, ZIP disks, floppy disks and tapes. Basically, PMD refers to any damage to the data storage media.

In conclusion...

Physical media damage is a huge problem in data recovery, but it doesn’t always mean the end of your data. Unfortunately, there are no guarantees when your drive crashes, so if you are lucky, the damage won’t be too severe and data recovery services may hold the key to getting your important data back.