Data recovery is the process of recovering data from storage media which cannot be accessed normally. Data can be successfully recovered from a wide range of storage media formats including hard disk drives, CDs, DVDs, RAID, USB drives and SD cards. Data recovery experts classify the causes of damage to storage media as either physical damage or logical damage. If you’ve saved important data since your last data backup, storage media damage can make attempting data recovery a necessary exercise.
Physical Damage
Physical damage to storage media can take all forms from simple things scratches, mechanical failures, electrical failures through to chemical, heat and fire damage. Often physical damage causes logical damage as well (see below). Physical damage is generally not repairable by the end user and requires data recovery experts. Further damage can be caused by incorrect techniques or an inappropriate work environment (experts work in clean rooms to prevent dust damage to delicate surfaces).
Data is often lost not because it couldn’t but, because users are too pessimistic about the chances of data recovery to try. Successful recovery of almost all data from a hard drive (HDD) which was crushed, burned and melted in the 2003 Space Shuttle Columbia crash allowed NASA to publish the results of an experiment in the April 2008 issue of a science journal, Physical Review E. Kroll Ontrack Inc. engineer Jon Edwards told Associated Press that, “When we got it, it was two hunks of metal stuck together. We couldn’t even tell it was a hard drive. It was burned and the edges were melted”.
Logical Damage
Logical damage is damage to the file system of a storage device which prevents it from being accessed normally by the host operating system. File systems can have different formats but, all are for organizing the storage of data on a storage medium so that it can be readily accessed, modified and added to.
A primary cause of logical damage is due to power outages interrupting the writing of a file structure to a storage medium leaving it in an inconsistent state. While operating systems can repair simple damage, in some cases a storage medium becomes inaccessible.
As with physical damage, some logical damage requires the storage device be shipped to a data recovery specialist’s laboratory. However, with logical damage there are also the options of specialized data recovery software or remote data recovery to try first.
Data recovery software can feature software tools to diagnose the storage media problem, recovery data and repair files and the file structure. Remote data recovery involves data recovery specialists using recovery software over a secure Internet connection.
