- Data loss
-
Data loss is an error condition in information systems in which information is destroyed by failures or neglect in storage, transmission, or processing. Information systems implement backup and disaster recovery equipment and processes to prevent data loss or restore lost data.
Data loss is distinguished from data unavailability, such as may arise from a network outage. Although the two have substantially similar effects, data unavailability is temporary, while data loss may be permanent. Data loss is also distinct from data spill, although the term data loss has been sometimes used in those incidents.[citation needed] Data loss incidents can, however, be also data spill incidents, in case media containing sensitive information is lost and subsequently acquired by another party. However, data spills are possible without the data being lost in the originating side.
Contents
Types of data loss
- Intentional Action
- Intentional deletion of a file or program
- Unintentional Action
- Accidental deletion of a file or program
- Misplacement of CDs or Memory sticks
- Administration errors
- Inability to read unknown file format
- Failure
- Power failure, resulting in data in volatile memory not being saved to permanent memory.
- Hardware failure, such as a head crash in a hard disk.
- A software crash or freeze, resulting in data not being saved.
- Software bugs or poor usability, such as not confirming a file delete command.
- Business failure (vendor bankruptcy), where data is stored with a software vendor using Software-as-a-service and SaaS data escrow has not been provisioned.
- Data corruption, such as file system corruption or database corruption.
- Disaster
- Natural disaster, earthquake, flood, tornado, etc.
- Fire
- Crime
Studies have consistently shown hardware failure and human error to be two most common causes of data loss, accounting for roughly three quarters of all incidents.[1] A commonly overlooked cause is a natural disaster. Although the probability is small, the only way to recover from data loss due to a natural disaster is to store backup data in a physically separate location.
Cost of data loss
The cost of a data loss event is directly related to the value of the data and the length of time that it is needed, but unavailable. Consider:
- The cost of continuing without the data
- The cost of recreating the data
- The cost of notifying users in the event of a compromise
Organizational responsibility
Recent statistics show the number of publicized data loss events involving sensitive data is on the rise,[2] in part due to recent legislation, including the landmark California SB 1386, requiring the notification of data loss. This and other legislation has forced organizations to notify victims that their identity has potentially been compromised.
Prevention
Data loss prevention can rarely be guaranteed. However, the frequency of data loss and the impact can be greatly mitigated by taking proper precautions. The different types of data loss demand different types of precautions. For example, multiple power circuits with battery backup and a generator will only protect against power failures. Similarly, using a journaling file system and RAID storage will only protect against certain types of software and hardware failure. Regular data backups are an important asset to have when trying to recover after a data loss event, but they don't do much to prevent user errors or system failures.
A well rounded approach to data protection has the best chance of avoiding data loss events. Such an approach will also include such mundane tasks as maintaining antivirus protection and network firewalls, as well as staying up to date with all published security fixes and system patches. User education is probably the most important, and most difficult, aspect of preventing data loss. Nothing else will prevent users from making mistakes that jeopardize data security.
Data recovery
Main article: Data Recovery
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 labs are usually dependent on type of damage and type of storage medium, as well as the required security or cleanroom procedures.
File system corruption can frequently be repaired by the user or the system administrator with the right software tools. A deleted file may not be overwritten on disk. It is more common for the operating system to simply delete its entry in the file system index. This can be easily reversed.
Successful recovery from a data loss generally requires an effective backup strategy. Without a 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.
The most convenient 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 going to be substantially different than recovering a whole system that was destroyed in a flood. An effective backup regimen will have 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 whole system destroyed in a flood.
Steps to be taken after data loss
Proper steps must always be taken in case of a data loss incident in order to preserve the recoverability of any lost data. First of all, all type of write operations should be avoided to the drive in question. This also includes starting up the computer. As, many OS including Windows, creates "temporary files" or "files required for booting" - those files may occupy and overwrite the area of the lost data and render it partially or completely unrecoverable. Needless to say, other write operations such as copying, deleting or altering the files should also be avoided.
The best and safest course of action would be that right upon realizing data loss, the computer must be safely shut down and the drive in question should be removed from the unit. After that, attach this drive to a secondary computer with a write blocker device and then proceed to perform data recovery either by the user himself or commercial data recovery services.
See also
References
- ^ The cost of lost data - Graziadio Business Report
- ^ "Etiolated Statistics". Etiolated Consumer\Citizen. http://www.etiolated.org/statistics. Retrieved 2007-06-05.
External links
- Data Loss Database - Reporting on data leaks, worldwide
- What To Do Right After A Data Loss Incident | Bitlevel explains things you must know after data loss
- Data Loss Warning Signs | LC Technology International, Inc.
- "Data Loss and Hard Drive Failure: Understanding the Causes and Costs", also includes recovery tips
- "How To: Recover deleted files (for Mac and Windows)"- Detailed how to articles on recovering documents, data, and files.
- The sounds of data loss: Failing Hard Drive Sounds
- Find lost data after emptied the recycle bin
Categories:- Computer data
- Data recovery
- Intentional Action
Wikimedia Foundation. 2010.
