Editing Data loss (section)

==Data recovery==
{{main|Data recovery}}
[[File:HD with toasty PCB.jpg|thumb|right|250px|Media that's suffered a catastrophic electronic failure requires data recovery in order to salvage its contents.]]

Data recovery is often performed by specialized commercial services that have developed often proprietary methods to recover data from physically damaged media. Service costs at [[data recovery lab]]s are usually dependent on type of damage and type of storage medium, as well as the required [[secure environment|security]] or [[cleanroom]] procedures.

File system corruption can frequently be repaired by the user or the system administrator. For example, a deleted file is typically not immediately overwritten on disk, but more often simply has its entry deleted from the file system index. In such a case, the deletion can be easily reversed.

Successful recovery from data loss generally requires implementation of an effective backup strategy. Without an implemented backup strategy, recovery requires reinstallation of programs and regeneration of data. Even with an effective backup strategy, restoring a system to the precise state it was in prior to the ''Data Loss Event'' is extremely difficult. Some level of compromise between granularity of recoverability and cost is necessary. Furthermore, a ''Data Loss Event'' may not be immediately apparent. An effective backup strategy must also consider the cost of maintaining the ability to recover lost data for long periods of time.

A highly effective backup system would have duplicate copies of every file and program that were immediately accessible whenever a ''Data Loss Event'' was noticed. However, in most situations, there is an inverse correlation between the value of a unit of data and the length of time it takes to notice the loss of that data. Taking this into consideration, many backup strategies decrease the granularity of restorability as the time increases since the potential ''Data Loss Event''. By this logic, recovery from recent ''Data Loss Events'' is easier and more complete than recovery from ''Data Loss Events'' that happened further in the past.

Recovery is also related to the type of ''Data Loss Event.'' Recovering a single lost file is substantially different from recovering an entire system that was destroyed in a disaster. An effective backup regimen has some proportionality between the magnitude of ''Data Loss'' and the magnitude of effort required to recover. For example, it should be far easier to restore the single lost file than to recover the entire system.

===Initial steps upon data loss===
If data loss occurs, a successful recovery must ensure that the deleted data is not over-written. For this reason write operations to the affected storage device should be avoided. This includes not starting the system to which the affected device is connected. This is because many operating systems create temporary files in order to boot, and these may overwrite areas of lost data — rendering it unrecoverable. Viewing web pages has the same effect — potentially overwriting lost files with the temporary HTML and image files created when viewing a web page. File operations such as copying, editing, or deleting should also be avoided.

Upon realizing data loss has occurred, it is often best to shut down the computer and remove the drive in question from the unit. Re-attach this drive to a secondary computer with a [[write blocker]] device and then attempt to recover lost data. If possible, create an image of the drive in order to establish a secondary copy of the data. This can then be tested on, with recovery attempted, abolishing the risk of harming the source data.{{Citation needed|date=October 2018}}