How data corruption works
Modern drives have advanced at an astounding rate in recent years, but despite all these innovations, media corruption still remains an issue in today’s data recovery industry. Before we delve into the deeper issues associated with media corruption, we need to understand what causes corruption and how it can be diagnosed within the context of data recovery.
What is media corruption?
Media corruption can be described as the loss or change of computer data during transmission or retrieval.
What causes media corruption?
Corruption is often caused when the data transfer process is interrupted or disturbed. This can be caused by electronics failure, power surges or internal mechanical problems.
How does media corruption damage data storage devices?
Corruption can affect any type of storage device; from hard drives to USB sticks, from RAID systems to floppy disks. Media corruption can modify or destroy important information which can render a storage device inoperable and inaccessible.
Why can media corruption cause so much damage?
Every device has a certain routine which performs when it boots up. During this process the device needs to access important information that tells it how to communicate with the host (whether it is plugged into a laptop, desktop or other piece of hardware). If this data is damaged or corrupted in some way, the device no longer knows how to boot, making it inoperable.
Can you see media corruption, and why is it such a problem?
In most cases you cannot see media corruption as it occurs deep within the data of a drive, or within the microchips that control the drive. In USB sticks, for example, media corruption occurs within the chip that controls the connection between the memory stick and the computer. It is therefore not possible to see (or quantify) the level of media corruption.
With modern mechanical hard drives it is also very difficult to see corruption; often it is only small areas of the drive that are affected. This minor corruption often only damages a few user files, but can still be enough to stop the entire drive being usable.
In severe instances of media corruption, this can affect the “system area” of the drive.
System area explained
The system area in a hard drive contains a series of commands which the hard drive needs to access in order to become accessible. It contains important information about the drive, including data capacity, model, serial number, and much more.
All mechanical hard drives need to access their system area in order to be usable; so if the system area becomes corrupted, they will no longer be recognised, and hence will be as much use as a brick!
Media corruption in older drives
Modern drives have many safeguards against media corruption, although it is impossible to prevent this completely.
With older drives, it is actually possible to see corruption when viewing the platters under a microscope; as you can see in the picture below.
Corruption: up close and personal
In the photograph below, we can see a magnified image of a platter. The vertical lines show where different sectors of the drive are located. These should be intersected with very thin horizontal lines, which divide up the tracks on the platter.
In the picture, we can see the thick lines that are a characteristic of severe media corruption.
Some final thoughts
It is clear that media corruption rarely causes a device to become inoperable, but it is possible. Even with today’s modern drives, severe corruption can result in poor recoveries and in some cases, can render the data completely unrecoverable.
The best way to ensure the safety of your data is to always keep an up to date backup. However, if you like to live on the edge, you can always risk not having backups and take a gamble the safety of your data - this option, not for the faint of heart, is definitely not recommended!
