Data recovery can be defined as a process of obtaining the information located on a storage device that cannot be accessed by the standard means due to its previous deletion or certain damage to the digital medium. Different approaches are used to regain the missing files, yet, only on the condition that their content is present somewhere within the storage. For instance, data recovery doesn’t cover the situations when a file has never been written to a persistent storage, like documents that were created but could not be eventually saved to the hard disk drive due to a power failure. Also, none of the existing restore methods can cope with the cases of permanent erasure which occurs when some other information occupies its storage space – under such circumstances, the lost files can only be retrieved from an external backup.
In general, data recovery techniques are divided into two types: software-based and ones involving the repair or replacement of the damaged hardware components in a laboratory setting. A software-based approach is employed in the majority of cases and involves the use of specialized utilities able to interpret the logical structure of the problem storage, read out the required data and deliver it to the user in a usable form for further copying. Physical repairs are conducted by specialists in the most severe instances, for example, when some mechanical or electrical parts of the drive no longer work properly – in this case, all the measures are directed towards a one-time extraction of the critical content, without the possibility of continued usage of the affected device.
