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For other uses of "Backup", see Backup (disambiguation).

Contents

In information technology, backup refers to making copies of data so that these additional copies may be used to restore the original after a data loss event. Information technology ( IT) as defined by the Information Technology Association of America (ITAA is "the study design development implementation support Debt AIDS Trade in Africa (or DATA) is a Multinational non-government organization founded in January 2002 in London by U2 's In the field of Information technology, data loss refers to the unforeseen loss of data or information These additional copies are typically called "backups. " Backups are useful primarily for two purposes. The first is to restore a state following a disaster (called disaster recovery). Disaster recovery is the process policies and procedures of restoring operations critical to the resumption of business including regaining access to data (records hardware software The second is to restore small numbers of files after they have been accidentally deleted or corrupted. [1] Backups are typically that last line of defense against data loss, and consequently the least granular and the least convenient to use. [2]

Since a backup system contains at least one copy of all data worth saving, the data storage requirements are considerable. Computer data storage, often called storage or memory, refers to Computer components devices and recording media that retain digital Organizing this storage space and managing the backup process is a complicated undertaking. A data repository model can be used to provide structure to the storage. In the modern era of computing there are many different types of data storage devices that are useful for making backups. A data storage device is a device for recording (storing information (data There are also many different ways in which these devices can be arranged to provide geographic redundancy, data security, and portability.

Before data is sent to its storage location, it is selected, extracted, and manipulated. Many different techniques have been developed to optimize the backup procedure. These include optimizations for dealing with open files and live data sources as well as compression, encryption, and de-duplication, among others. Many organizations and individuals try to have confidence that the process is working as expected and work to define measurements and validation techniques. It is also important to recognize the limitations and human factors involved in any backup scheme.

Due to a considerable overlap in technology, backups and backup systems are frequently confused with archives and fault-tolerant systems. An archive refers to a collection of historical records and also refers to the location in which these records are kept This article contains specific implementations of fault tolerant systems Backups differ from archives in the sense that archives are the primary copy of data and backups are a secondary copy of data. Archives are the primary copy of the item, usually put away for future use, while backups are the secondary copy, kept on hand to replace the original item. Backup systems differ from fault-tolerant systems in the sense that backup systems assume that a fault will cause a data loss event and fault-tolerant systems assume a fault will not.

Storage, the base of a backup system

Data repository models

Any backup strategy starts with a concept of a data repository. The backup data needs to be stored somehow and probably should be organized to a degree. It can be as simple as a sheet of paper with a list of all backup tapes and the dates they were written or a more sophisticated setup with a computerized index, catalog, or relational database. Different repository models have different advantages. This is closely related to choosing a backup rotation scheme. A backup rotation scheme is a method for effectively backing up data where multiple media (such as tapes) are used in the backup process

Unstructured 
An unstructured repository may simply be a stack of floppy disks or CD-R/DVD-R media with minimal information about what was backed up and when. This is the easiest to implement, but probably the least likely to achieve a high level of recoverability.
Full + Incrementals 
A Full + Incremental repository aims to make storing several copies of the source data more feasible. An incremental backup is a Backup method where multiple backups are kept (not just the last one At first, a full backup (of all files) is taken. After that an incremental backup (of only the files that have changed since the previous full or incremental backup) can be taken. Restoring whole systems to a certain point in time would require locating the full backup taken previous to that time and all the incremental backups taken between that full backup and the particular point in time to which the system is supposed to be restored. This model offers a high level of security that something can be restored and can be used with removable media such as tapes and optical disks. The downside is dealing with a long series of incrementals and the high storage requirements. [3]
Full + Differential 
A full + differential backup differs from a full + incremental in that after the full backup is taken, each partial backup captures all files created or changed since the full backup, even though some may have been included in a previous partial backup. Its advantage is that a restore involves recovering only the last full backup and then overlaying it with the last differential backup. [4]
Mirror + Reverse Incrementals
A Mirror + Reverse Incrementals repository is similar to a Full + Incrementals repository. In Computing, a mirror is an exact copy of a Data set On the Internet, a mirror site is an exact copy of another Internet site rsync is a Software application for Unix systems which synchronizes files and directories from one location to another while minimizing The difference is instead of an aging full backup followed by a series of incrementals, this model offers a mirror that reflects the system state as of the last backup and a history of reverse incrementals. One benefit of this is it only requires an initial full backup. Each incremental backup is immediately applied to the mirror and the files they replace are moved to a reverse incremental. This model is not suited to use removable media since every backup must be done in comparison to the mirror.
Continuous data protection 
This model takes it a step further and instead of scheduling periodic backups, the system immediately logs every change on the host system. Continuous data protection (CDP also called continuous backup or real-time backup, refers to backup of Computer Data by automatically saving This is generally done by saving byte or block-level differences rather than file-level differences. [5] It differs from simple disk mirroring in that it enables a roll-back of the log and thus restore of old image of data. In Data storage, disk mirroring or RAID1 is the replication of logical disk volumes onto separate physical Hard disks in real time

Storage media

Regardless of the repository model that is used, the data has to be stored on some data storage medium somewhere.

Magnetic tape 
Magnetic tape has long been the most commonly used medium for bulk data storage, backup, archiving, and interchange. Magnetic tape has been used for Data storage for over 50 years Tape has typically had an order of magnitude better capacity/price ratio when compared to hard disk, but recently the ratios for tape and hard disk have become a lot closer. [6] There are myriad formats, many of which are proprietary or specific to certain markets like mainframes or a particular brand of personal computer. Tape is a sequential access medium, so even though access times may be poor, the rate of continuously writing or reading data can actually be very fast. Some new tape drives are even faster than modern hard disks.
Hard disk 
The capacity/price ratio of hard disk has been rapidly improving for many years. A hard disk drive ( HDD) commonly referred to as a hard drive, hard disk, or fixed disk drive, is a Non-volatile storage device This is making it more competitive with magnetic tape as a bulk storage medium. The main advantages of hard disk storage are low access times, availability, capacity and ease of use. [7] External disks can be connected via local interfaces like SCSI, USB, FireWire, or eSATA, or via longer distance technologies like Ethernet, iSCSI, or Fibre Channel. The IEEE 1394 interface is a serial bus Interface standard for high-speed communications and Isochronous real-time data transfer frequently Ethernet is a family of frame -based Computer networking technologies for Local area networks (LANs In computing the iSCSI (for " Internet SCSI " protocol allows clients (called initiators) to send SCSI commands ( ''CDBs'' Fibre Channel, or FC, is a Gigabit -speed network technology primarily used for Storage networking. Some disk-based backup systems, such as Virtual Tape Libraries, support data de-duplication which can dramatically reduce the amount of disk storage capacity consumed by daily and weekly backup data.
Optical disc 
A recordable CD can be used as a backup device. A CD-R ( C ompact D isc- R ecordable is a variation of the Compact Disc invented by Philips and Sony. One advantage of CDs is that they can be restored on any machine with a CD-ROM drive. In addition, recordable CD's are relatively cheap. A CD-R ( C ompact D isc- R ecordable is a variation of the Compact Disc invented by Philips and Sony. Another common format is recordable DVD. DVD recordable and DVD rewritable refer to DVD Optical disc formats that can be recorded (written "burned" either write once Many optical disk formats are WORM type, which makes them useful for archival purposes since the data can't be changed. Other rewritable formats can also be utilized such as CD-RW or DVD-RAM. Compact Disc ReWritable (CD-RW is a rewritable Optical disc format DVD-RAM ( DVD – Random Access Memory) is a disc specification presented in 1996 by the DVD Forum, which specifies rewritable DVD-RAM media and the appropriate The newer HD-DVDs and Blu-ray Discs dramatically increase the amount of data possible on a single optical storage disk, though, as yet, the hardware may be cost prohibitive for many people.
Floppy disk 
During the 1980s and early 1990s, many personal/home computer users associated backup mostly with copying floppy disks. A floppy disk is an increasingly Obsolete data storage medium that is composed of a disk of thin flexible ("floppy" Magnetic storage medium encased The low data capacity of a floppy disk makes it an unpopular and obsolete choice today. [8]
Solid state storage 
Also known as flash memory, thumb drives, USB flash drives, CompactFlash, SmartMedia, Memory Stick, Secure Digital cards, etc. A solid-state drive ( SSD) is a Data storage device that uses solid-state memory to store persistent Data. Flash memory is non-volatile computer memory that can be electrically erased and reprogrammed CompactFlash ( CF) is a Mass storage device format used in portable electronic devices SmartMedia is a flash Memory card standard owned by Toshiba, with capacities ranging from 0 Memory Stick is a removable flash Memory card format launched by Sony in October 1998, and is also used in general to describe the whole family Secure Digital ( SD) is a non-volatile Memory card format developed by Matsushita, SanDisk, and Toshiba for use in , these devices are relatively costly for their low capacity, but offer excellent portability and ease-of-use.
Remote backup service 
As broadband internet access becomes more widespread, remote backup services are gaining in popularity. A remote online or managed backup service is a service that provides users with an online system for backing up and storing Computer files Managed backup providers Broadband Internet access, often shortened to just Broadband, is high-speed Internet access—typically contrasted with dial-up access over a Modem Backing up via the internet to a remote location can protect against some worst-case scenarios such as fire, flood, earthquake or nuclear strike which would destroy any backups in the immediate vicinity along with everything else. A drawback to a remote backup service is that an internet connection is usually substantially slower than the speed of local data storage devices, so this can be a problem for people with large amounts of data. It also has the risk associated with putting control of personal or sensitive data in the hands of a third party.

Managing the data repository

Regardless of the data repository model or data storage media used for backups, a balance needs to be struck between accessibility, security and cost.

On-line 
On-line backup storage is typically the most accessible type of data storage, which can begin restore in milliseconds time. A good example would be an internal hard disk or a disk array (maybe connected to SAN). A disk array is a Disk storage system which contains multiple Disk drives It is differentiated from a Disk enclosure, in that an array has Cache In Information technology, a storage area network ( SAN) is an architecture to attach remote computer storage devices (such as Disk arrays tape libraries This type of storage is very convenient and speedy, but is relatively expensive. On-line storage is vulnerable to being deleted or overwritten, either by accident, or in the wake of a data-deleting virus payload. A computer virus is a Computer program that can copy itself and infect a computer without permission or knowledge of the user
Near-line 
Near-line storage is typically less accessible and less expensive than on-line storage, but still useful for backup data storage. Nearline storage (where Nearline is a contraction of Near -on' line') is a term used in computer science to describe an intermediate type of data storage A good example would be a tape library with restore times ranging from seconds to a few minutes. A mechanical device is usually involved in moving media units from storage into a drive where the data can be read or written.
Off-line 
Off-line storage is similar to near-line, except it requires human interaction to make storage media available. Computer data storage, often called storage or memory, refers to Computer components devices and recording media that retain digital This can be as simple as storing backup tapes in a file cabinet. Media access time can be be anywhere from a few seconds to more than an hour.
Off-site vault 
To protect against a disaster or other site-specific problem, many people choose to send backup media to an off-site vault. In Computing, off-site data protection, or vaulting, is the strategy of sending critical data out of the main location ( off the main site) as The vault can be as simple as the System Administrator’s home office or as sophisticated as a disaster hardened, temperature controlled, high security bunker that has facilities for backup media storage.
Backup site, Disaster Recovery Center or DR Center
In the event of a disaster, the data on backup media will not be sufficient to recover. A backup site is a location where an organization can easily relocate following a disaster such as Fire, Flood, Terrorist threat or other disruptive event A backup site is a location where an organization can easily relocate following a disaster such as Fire, Flood, Terrorist threat or other disruptive event Computer systems onto which the data can be restored and properly configured networks are necessary too. Some organizations have their own data recovery centers that are equipped for this scenario. Other organizations contract this out to a third-party recovery center. Note that because DR site is itself a huge investment, backup is very rarely considered preferred method of moving data to DR site. More typical way would be remote disk mirroring, which keeps the DR data as up-to-date as possible. In Data storage, disk mirroring or RAID1 is the replication of logical disk volumes onto separate physical Hard disks in real time

Selection, extraction and manipulation of data

Selection and extraction of file data

Deciding what to back up at any given time is a harder process than it seems. By backing up too much redundant data, the data repository will fill up too quickly. Backing up an insufficient amount of data can eventually lead to the loss of critical information.

Copying files 
Making copies of files is the simplest and most common way to perform a backup. File copying is creation of a new file which has the same content as an existing file A means to perform this basic function is included in all backup software and all operating systems.
Filesystem dump 
Instead of copying files within a filesystem, a copy of the whole filesystem itself can be made. This is also known as a raw partition backup and is related to disk imaging. A disk image is a single File containing the complete contents and structure representing a data storage medium or device such as a Hard drive, CD, or The process usually involves unmounting the filesystem and running a program like dump. dump is a Unix program used to back up File systems. It operates on blocks, below filesystem abstractions such as files This type of backup has the possibility of running faster than a backup that simply copies files. A feature of some dump software is the ability to restore specific files from the dump image.
Identification of changes 
Some filesystems have an archive bit for each file that says it was recently changed. Some backup software looks at the date of the file and compares it with the last backup, to determine whether the file was changed.
Block Level Incremental 
A more sophisticated method of backing up changes to files is to only back up the blocks within the file that changed. This requires a higher level of integration between the filesystem and the backup software.
Versioning file system 
A versioning filesystem keeps track of all changes to a file and makes those changes accessible to the user. A versioning file system is any computer File system which allows a Computer file to exist in several versions at the same time Generally this gives access to any previous version, all the way back to the file's creation time. An example of this is the Wayback versioning filesystem for Linux. [9]

Selection and extraction of live data

If a computer system is in use while it is being backed up, the possibility of files being open for reading or writing is real. If a file is open, the contents on disk may not correctly represent what the owner of the file intends. This is especially true for database files of all kinds. The term fuzzy backup can be used to describe a backup of live data that looks like it ran correctly, but does not represent the state of the data at any single point in time. A fuzzy backup is a secondary (or Backup) copy of data file(s or directories that were in one state when the backup started but in a different state by the time the backup This is because the data being backed up changed in the period of time between when the backup started and when it finished. For databases in particular, fuzzy backups are worthless.

Snapshot backup 
A snapshot is an instantaneous function of some storage systems that presents a copy of the filesystem as if it was frozen in a specific point in time, often by a copy-on-write mechanism. In computer file systems, a snapshot is a copy of a set of files and directories as they were at a particular point in the past Copy-on-write (sometimes referred to as "COW" is an optimization strategy used in Computer programming. An effective way to back up live data is to temporarily quiesce it (e. g. close all files), take a snapshot, and then resume live operations. At this point the snapshot can be backed up through normal methods. [10] While a snapshot is very handy for viewing a filesystem as it was at a different point in time, it is hardly an effective backup mechanism by itself.
Open file backup 
Many backup software packages feature the ability to handle open files in backup operations. Some simply check for openness and try again later. File locking is useful for regulating access to open files. File locking is a mechanism that enforces access to a Computer file by only one user or process at any specific time
When attempting to understand the logistics of backing up open files, one must consider that the backup process could take several minutes to back up a large file such as a database. In order to back up a file that is in use, it is vital that the entire backup represent a single-moment snapshot of the file, rather than a simple copy of a read-through. This represents a challenge when backing up a file that is constantly changing. Either the database file must be locked to prevent changes, or a method must be implemented to ensure that the original snapshot is preserved long enough to be copied, all while changes are being preserved. Backing up a file while it is being changed, in a manner that causes the first part of the backup to represent data before changes occur to be combined with later parts of the backup after the change results in a corrupted file that is unusable, as most large files contain internal references between their various parts that must remain consistent throughout the file.
Cold database backup 
During a cold backup, the database is closed or locked and not available to users. The datafiles do not change during the backup process so the database is in a consistent state when it is returned to normal operation. [11]
Hot database backup 
Some database management systems offer a means to generate a backup image of the database while it is online and usable ("hot"). This usually includes an inconsistent image of the data files plus a log of changes made while the procedure is running. Upon a restore, the changes in the log files are reapplied to bring the database in sync. [12]

Selection and extraction of metadata

Not all information stored on the computer is stored in files. Accurately recovering a complete system from scratch requires keeping track of this non-file data too.

System description 
System specifications are needed to procure an exact replacement after a disaster.
Boot sector 
The boot sector can sometimes be recreated more easily than saving it. A boot sector (sometimes called a bootblock) is a sector of a Hard disk, Floppy disk, or similar Data storage device that contains Still, it usually isn't a normal file and the system won't boot without it.
Partition layout 
The layout of the original disk, as well as partition tables and filesystem settings, is needed to properly recreate the original system. Disk partitioning is the creation of separate divisions of a Hard disk drive using Partition editors Once a disk is divided into several partitions directories and
File metadata 
Each file's permissions, owner, group, ACLs, and any other metadata need to be backed up for a restore to properly recreate the original environment. Metadata ( meta data, or sometimes metainformation) is "data about data" of any sort in any media
System metadata 
Different operating systems have different ways of storing configuration information. Windows keeps a registry of system information that is more difficult to restore than a typical file. The Windows registry is a directory which stores settings and options for the Operating system for Microsoft Windows 32-bit versions 64-bit versions and

Manipulation of data

It is frequently useful to manipulate the data being backed up to optimize the backup process. These manipulations can improve backup speed, restore speed, data security, and media usage.

Compression 
Various schemes can be employed to shrink the size of the source data to be stored so that uses less storage space. Compression is frequently a built-in feature of tape drive hardware.
De-duplication 
When multiple similar systems are backed up to the same destination storage device, there exists the potential for much redundancy within the backed up data. Deduplication Capacity optimization technologies are similar to Data compression technologies but they look for redundancy of very large sequences of bytes across very large For example, if 20 Windows workstations were backed up to the same data repository, they might share a common set of system files. The data repository only needs to store one copy of those files to be able to restore any one of those workstations. This technique can be applied at the file level or even on raw blocks of data, potentially resulting in a massive reduction in required storage space. Deduplication can occur on a server before any data moves to backup media, sometimes referred to as source/client side deduplication. This approach also reduces bandwidth required to send backup data to its target media. The process can also occur at the target storage device, sometimes referred to as inline or back-end deduplication;
Duplication 
Sometimes backup jobs are duplicated to a second set of storage media. Replication is the process of sharing information so as to ensure consistency between redundant resources such as Software or Hardware components to improve reliability This can be done to rearrange the backup images to optimize restore speed, to have a second copy at a different location or on a different storage medium.
Encryption 
High capacity removable storage media such as backup tapes present a data security risk if they are lost or stolen. [13] Encrypting the data on these media can mitigate this problem, but presents new problems. First, encryption is a CPU intensive process that can slow down backup speeds. Second, once data has been encrypted, it can not be effectively compressed (although since redundant data makes cryptanalytic attacks easier many encryption routines compress the data as an integral part of the encryption process). Third, the security of the encrypted backups is only as effective as the security of the key management policy.
Staging 
Sometimes backup jobs are copied to a staging disk before being copied to tape. Disk staging is using disks as an additional temporary stage of Backup process before finally storing backup to tape. This process is sometimes referred to as D2D2T, an acronym for Disk to Disk to Tape. This can be useful if there is a problem matching the speed of the final destination device with the source device as is frequently faced in network-based backup systems. It can also serve as a centralized location for applying other data manipulation techniques.

Managing the backup process

It is important to understand that backup is a process. As long as new data is being created and changes are being made, backups will need to be updated. Individuals and organizations with anything from one computer to thousands (or even millions) of computer systems all have requirements for protecting data. While the scale is different, the objectives and limitations are essentially the same. Likewise, those who perform backups need to know to what extent they were successful, regardless of scale.

Objectives

Recovery Point Objective (RPO) 
The point in time that the restarted infrastructure will reflect. Essentially, this is the roll-back that will be experienced as a result of the recovery. The most desirable RPO would be the point just prior to the data loss event. Making a more recent recovery point achievable requires increasing the frequency of synchronization between the source data and the backup repository. File synchronization (or 'synching' or 'syncing' in computing is the process of making sure that two or more locations contain the same up-to-date files. [14]
Recovery Time Objective (RTO) 
The amount of time elapsed between disaster and restoration of business functions. [15]
Data security 
In addition to preserving access to data for its owners, data must be restricted from unauthorized access. Backups must be performed in a manner that does not compromise the original owner's undertaking. This can be achieved with data encryption and proper media handling policies.

Limitations

An effective backup scheme will take into consideration the limitations of the situation.

Backup window 
The period of time when backups are permitted to run on a system is called the backup window. This is typically the time when the system see the least usage and the backup process will have the least amount of interference with normal operations. The backup window is usually planned with users' convenience in mind. If a backup extends past the defined backup window, a decision is made whether it is more beneficial to abort the backup or to increase the backup window.
Performance impact 
All backup schemes have some performance impact on the system being backed up. For example, for the period of time that a computer system is being backed up, the hard drive is busy reading files for the purposes of the backup, and its full bandwidth is no longer available for other tasks. Such impacts should be analyzed.
Costs of hardware, software, labor 
All types of storage media have a finite capacity with a real cost. Matching the correct amount of storage capacity (over time) with the backup needs is an important part of the design of a backup scheme. Any backup scheme has some labor requirement, but complicated schemes have considerably higher labor requirements. The cost of commercial backup software can also be considerable.
Network Bandwidth 
Distributed backup systems can be impacted by limited network bandwidth.

Implementation

Meeting the defined objectives in the face of the above limitations can be a difficult task. The tools and concepts below can make that task more achievable.

Scheduling 
Using a Job scheduler can greatly improve the reliability and consistency of backups by removing part of the human element. A job scheduler is an enterprise software application that is in charge of unattended background executions commonly known for historical reasons as Batch processing. Many backup software packages include this functionality.
Authentication 
Over the course of regular operations, the user accounts and/or system agents that perform the backups need to be authenticated at some level. The power to copy all data off of or onto a system requires unrestricted access. Using an authentication mechanism is a good way to prevent the backup scheme from being used for unauthorized activity.
Chain of trust 
Removable storage media are physical items and must only be handled by trusted individuals. In computer security a chain of trust is established by validating each component of Hardware and Software from the bottom up A data storage device is a device for recording (storing information (data Establishing a chain of trusted individuals (and vendors) is critical to defining the security of the data.

Measuring the process

To ensure that the backup scheme is working as expected, the process needs to include monitoring key factors and maintaining historical data.

Backup validation 
(also known as "Backup Success Validation") The process by which owners of data can get information regarding how their data was backed up. Backup validation is the process whereby owners of Computer Data may examine how their data was backed up in order to understand what their risk of Data loss This same process is also used to prove compliance to regulatory bodies outside of the organization, for example, an insurance company might be required under HIPAA to show "proof" that their patient data are meeting records retention requirements[16]. The Health Insurance Portability and Accountability Act ( HIPAA) was enacted by the U Disaster, data complexity, data value and increasing dependence upon ever-growing volumes of data all contribute to the anxiety around and dependence upon successful backups to ensure business continuity. Business Continuity is the activity performed by an organization to ensure that critical business functions will be available to customers suppliers regulators and other entities For that reason, many organizations rely on third-party or "independent" solutions to test, validate, and optimize their backup operations (backup reporting).
Reporting 
In larger configurations, reports are useful for monitoring media usage, device status, errors, vault coordination and other information about the backup process.
Logging 
In addition to the history of computer generated reports, activity and change logs are useful for monitoring backup system events.
Validation 
Many backup programs make use of checksums or hashes to validate that the data was accurately copied. A checksum is a form of Redundancy check, a simple way to protect the integrity of data by detecting errors in data that are sent through space ( Telecommunications A hash function is any well-defined procedure or mathematical function for turning some kind of Data into a relatively small integer, that may These offer several advantages. First, they allow data integrity to be verified without reference to the original file: if the file as stored on the backup medium has the same checksum as the saved value, then it is very probably correct. Second, some backup programs can use checksums to avoid making redundant copies of files, to improve backup speed. This is particularly useful for the de-duplication process.
Monitored Backup 
Backup processes are monitored by a third party monitoring center. This center alerts users to any errors that occur during automated backups. Monitored backup requires software capable of pinging the monitoring center's servers in the case of errors.

Lore

Advice

Events

See also

References

  1. ^ Why do I need to Backup (sic) my Files?. This page is a glossary of backup terms. See also Backup backup policy - an organisation's procedures and rules for ensuring that adequate Backup software is a computer program used to perform a complete Back up of a file data database system or Server. This is a list of Backup software ( Software A backup rotation scheme is a method for effectively backing up data where multiple media (such as tapes) are used in the backup process An incremental backup is a Backup method where multiple backups are kept (not just the last one Computer data storage, often called storage or memory, refers to Computer components devices and recording media that retain digital Data proliferation refers to the unprecedented amount of Data, structured and unstructured that business and government continue to generate at an unprecedented File synchronization (or 'synching' or 'syncing' in computing is the process of making sure that two or more locations contain the same up-to-date files. An information repository is an easy to deploy secondary tier of Data storage that can comprise multiple networked data storage technologies running on diverse Operating Disaster recovery and Business continuity refers to an organization’s ability to recover from a Disaster and/or unexpected event and resume or continue operations Digital preservation is the management of Digital information over time Reversible computing includes any Computational process that is (at least to some close approximation Reversible, i Retrieved on 2007-03-10
  2. ^ Backup – Your last line of defense. Retrieved on 2007-03-10
  3. ^ Incremental Backup. Retrieved on 2007-03-10
  4. ^ Differential Backup. Retrieved on 2007-03-10
  5. ^ Continuous Protection white paper. (2005-10-01). Retrieved on 2007-03-10
  6. ^ Disk to Disk Backup versus Tape - War or Truce? (2004-12-09). Retrieved on 2007-03-10
  7. ^ Bye Bye Tape, Hello 5.3TB eSATA. Retrieved on 2007-04-22. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 1500 - Portuguese Navigator Pedro Álvares Cabral becomes the first European to sight Brazil.
  8. ^ Choosing a Data Backup. Retrieved on 2007-03-10
  9. ^ Wayback: A User-level Versioning File System for Linux (2004). Retrieved on 2007-03-10
  10. ^ What is a Snapshot backup?. Retrieved on 2007-03-10
  11. ^ Oracle Tips (1997-12-10). Retrieved on 2007-03-10
  12. ^ Oracle Tips (1997-12-10). Retrieved on 2007-03-10
  13. ^ Backups tapes a backdoor for identity thieves (2004-04-28). Retrieved on 2007-03-10
  14. ^ Recovery Point Objective Definition. Retrieved on 2007-03-10
  15. ^ Recovery Time Objective Definition. Retrieved on 2007-03-07
  16. ^ HIPAA Advisory. Retrieved on 2007-03-10
  17. ^ Credit Lyonnais fire, 1996
  18. ^ "...destruction of crucial bank archives..."
  19. ^ A Chronology of Data Breaches Privacy Rights Clearinghouse, San Diego
  20. ^ "Telia server outage causes massive loss of email messages" (2008-01-07). Privacy Rights Clearinghouse (PRC is a project of the Utility Consumers' Action Network (UCAN an American 501(c(3 Non-profit consumer advocacy organization 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 1325 - Alfonso IV becomes King of Portugal. 1558 - France takes Calais, the last continental blog. anta. net. ISSN 1797-1993. An International Standard Serial Number ( ISSN) is a unique eight-digit number used to identify a print or electronic Periodical publication.  
  21. ^ Telia Sonera to compensate clients over email crash

Dictionary

backup

-noun

  1. A reserve or substitute.
  2. (computing) A copy of a file or record, stored separately from the original, that can be used to recover the original if it is destroyed or damaged.
  3. An accumulation of material that halts the flow or movement of something.

-adjective

  1. standby, reserve or extra
  2. (computing) That is intended as a backup.
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