Data Loss

Data loss is one of Information Technology industry’s most misunderstood concepts. Very little information has been made public about data loss, and the information that does exist is inconsistent. Due to the mixed messages they receive, users find it difficult to properly evaluate their data loss situations and make educated decisions to recover from them.

Most lost data is not lost at all; it has simply become inaccessible to the user. Hundreds of thousands of gigabytes (GB) of data have been lost simply because users were not aware of their options and gave up hope of recovery.

How does a hard disk drive store data?

Hard disk drives store data on one or more metal oxide platters. These platters, which spin at a rate of 3600-10,000 revolutions per minute, hold magnetic charges. A read-write head attached to an actuator arm actually floats on a cushion of air, 1-2 micro-inches (one millionth of an inch) above the surface of the platters. Data flows to and from these heads via electrical connections. Any force that alters this process may cause data loss to occur.

More data is being stored in smaller spaces. Ten years ago hard drives stored 40 Megabytes (MB) of data. Today’s hard drives store up to 80 gigabytes (GB) on a smaller surface than the drives of a decade ago. Increasing storage capacities amplify the impact of data loss. As more and more data is stored in smaller and denser areas, mechanical precision becomes crucial.

As a part of this advancing technology, the drive tolerance (distance between the read-write head and the platter where data is stored) is steadily decreasing. A slight nudge, a power surge or a contaminant introduced into the drive may cause the head to touch the platter, resulting in a head crash. In some situations, the data residing in the area touched by the head may be permanently destroyed.

The current tolerance drives is 1-2 micro-inches (millionths of an inch). Comparatively, a speck of dust is 4-8 micro-inches and human hair 10 micro-inches. Contaminants of this size can cause serious data damage.