back up

Near-line storage
Near-line storage is used by corporations, including data warehouses, as an inexpensive, scalable way to store large volumes of data. Near-line storage devices include DAT and DLT tapes (sequential access); optical storage such as CD-ROM, DVD, and Blu-ray; magneto-optical which utilize magnetic heads with an optical reader; and also slower P-ATA and SATA hard disk drives. Retrieval of data is slower than SCSI hard disk which is usually connected directly to servers or in a SAN environment. Near-Line implies that whatever media the information is stored on, it can be accessed via a tape library or some other method electronically as opposed to off-line which signified some human intervention is required, such as retrieving and mounting a tape. Near-line can be slower, but the type of data (historical archives, backup data, video, and others) dictates that the information will not require instant access and high throughput that SAN and SCSI can provide and is less expensive per byte.

Network-attached storage(NAS)
A network-attached storage (NAS) device is a server that is dedicated to nothing more than file sharing. NAS does not provide any of the activities that a server in a server-centric system typically provides, such as e-mail, authentication, or file management. NAS allows more hard disk storage space to be added to a network that already utilizes servers without shutting them down for maintenance and upgrades. With a NAS device, storage is not an integral part of the server. Instead, in this storage-centric design, the server still handles all of the processing of data but a NAS device delivers the data to the user. A NAS device does not need to be located within the server but can exist anywhere in a LAN and can be made up of multiple networked NAS devices.

Nyquist’s Law
Also called Nyquist’s Theorem. Before sound as acoustic energy can be manipulated on a computer, it must first be converted to electrical energy (using a transducer such as a microphone) and then transformed through an analog-to-digital converter into a digital representation. This is all accomplished by sampling the continuous input waveform a certain number of times per second. The more often a wave is sampled the more accurate the digital representation. Nyquist’s Law, named in 1933 after scientist Harry Nyquist, states that a sound must be sampled at least twice its highest analog frequency in order to extract all of the information from the bandwidth and accurately represent the original acoustic energy. Sampling at slightly more than twice the frequency will make up for imprecisions in filters and other components used for the conversion.

Light archive
In reference to data storage, an archive that can be accessed by many authorized users. Access to the data is open to all the members of the “community” that have a need for the data.

Lightbox
In digital asset management (DAM) systems, an area within the web site (or web service) or other internal DAM where users can create and store a list of assets they want to reference or use at a later time. Lightboxes are common on stock photo web sites where registered users can store images until they are ready to download them.

Linear tape open
Linear tape open (LTO) is a technology that was developed jointly by HP, IBM, and Certance (Seagate) to provide a clear and viable choice in an increasingly complex array of tape storage options.  LTO technology is an “open format” technology, which means that users have multiple sources of product and media. The open nature of the technology also provides a means of enabling compatibility between different vendors’ offerings.

Local area network
A local area network (LAN) is a communications infrastructure—typically Ethernet—designed to use dedicated wiring over a limited distance (typically a diameter of less than five kilometers) to connect a large number of intercommunicating nodes.

Lost cluster
Also called a lost allocation unit, or a lost file fragment. A data fragment that does not belong to any file, according to the system’s file management system, and, therefore, is not associated with a file name in the file allocation table. Lost clusters can result from files not being closed properly, from shutting down a computer without first closing an application, or from ejecting a storage medium, such as a floppy disk, from the disk drive while the drive is reading or writing.

Low-level format
(n.) A formatting method that creates the tracks and sectors on a hard disk. Low-level formatting creates the physical format that dictates where data is stored on the disk. Modern hard drives are low-level formatted at the factory for the life of the drive. A PC cannot perform an LLF on a modern IDE/ATA or SCSI hard disk, and doing so would destroy the hard disk. A low-level format is also called a physical format.

(v.) The process of performing low-level formatting.

iFCP
The Internet Fibre Channel Protocol (iFCP) allows an organization to extend Fibre Channel storage networks over the Internet by using TCP/IP. TCP is responsible for managing congestion control as well as error detection and recovery services. iFCP allows an organization to create an IP SAN fabric that minimizes the Fibre Channel fabric component and maximizes use of the company’s TCP/IP infrastructure.

Image

• In computer science an image is an exact replica of the contents of a storage device (a hard disk drive or CD-ROM for example) stored on a second storage device.
• Often used in place of the term digital image, which is an optically formed duplicate or other reproduction of an object formed by a lens or mirror.

Incremental backup
Any backup in which only the data objects that have been modified since the time of some previous backup are copied. Incremental backup is a collective term for cumulative incremental backups and differential incremental backups. Contrast with an archival, or full, backup, in which all files are backed up regardless of whether they have been modified since the last backup.

Information classification and management
Information classification and management (ICM) is a class of application-independent software that use advanced indexing, classification, policy and data access capabilities to automate data management activities above the storage layer.

Infrastructure
The combined set of hardware, software, networks, facilities, and other components (including all of the information technology) necessary to develop, test, deliver, monitor, control, or support IT services. Associated people, processes, and documentation are not part of an infrastructure.

Intelligent information management
Intelligent information management (IIM) is a set of processes and underlying technology solutions that enables organizations to understand, organize, and manage all sorts of data types (for example, general files, databases, and e-mails). Key attributes that define an IIM solution include the following:

Interrecord gap
The space between two consecutive physical blocks on a data recording medium, such as a hard drive or a magnetic tape. Interrecord gaps are used as markers for the end of data and also as safety margins for data overwrites. An interrecord gap is also referred to as an interblock gap.

Internet small computer systems interface
Internet small computer systems interface (iSCSI) is a transport protocol that enables the SCSI protocol to be carried over a TCP-based IP network. iSCSI was standardized by the Internet Engineering Task Force and described in RFC 3720.

IP storage
A technology being standardized under the IP Storage (IPS) IETF Working Group. Same as SoIP.

Heterogeneous environment
An IT environment that includes computers, operating systems, platforms, databases, applications, and other components from different vendors.

Hierarchical storage management
Hierarchical storage management (HSM) is a data storage system that automatically moves data between high-cost and low-cost storage media. HSM systems exist because high-speed storage devices, such as hard disk drives, are more expensive (per byte stored) than slower devices, such as optical discs and magnetic tape drives. While it would be ideal to have all data available on high-speed devices all the time, this is prohibitively expensive for many organizations. Instead, HSM systems store the bulk of the enterprise’s data on slower devices, and then copy data to faster disk drives when needed. In effect, HSM turns the fast disk drives into caches for the slower mass storage devices. The HSM system monitors the way data is used and makes best guesses as to which data can safely be moved to slower devices and which data should stay on the hard disks.

High availability
The availability of resources in a computer system in the wake of component failures in the system. High availability can be achieved in a variety of ways—from solutions that use custom and redundant hardware to ensure availability to solutions that provide software solutions using off-the-shelf hardware components. The former class of solutions provides a higher degree of availability, but is significantly more expensive than the latter class. This high cost has led to the popularity of the latter class, with almost all vendors of computer systems offering various high availability products. Typically, these products survive single points of failure in the system.

High-level format
(n.) A formatting method that initializes portions of the hard disk and creates the file system structures on the disk, such as the master boot record and the file allocation tables. High-level formatting is typically done to erase the hard disk and reinstall the operating system back onto the disk drive.

(v.) The process of performing high-level formatting.

Holographic data storage
A mass storage technology that uses three-dimensional holographic images to enable more information to be stored in a much smaller space. In holographic storage, at the point where the reference beam and the data carrying signal beam intersect, the hologram is recorded in the light sensitive storage medium.

Hosted service
A service in which day-to-day related management responsibilities are transferred to the service provider. The person or organization that owns or has direct oversight of the organization or system being managed is referred to as the offerer, client, or customer. The person or organization that accepts and provides the hosted service is regarded as the service provider. Typically, the offerer remains accountable for the functionality and performance of a hosted service and does not relinquish the overall management responsibility of the organization or system.

Hot backup
A technique used in data storage and backup that enables a system to perform a routine backup of data, even if the data is being accessed by a user. Hot backups are a popular backup solution for multi-user systems as no downtime to perform the backup is required. If a user alters the data during the backup process (for example, makes changes at the exact moment the backup system is processing that data) the final version of the backup may not reflect those changes. Hot backup may also be called a dynamic backup or active backup.

Hot potato routing
A form of routing in which the nodes of a network have no buffer to store packets in before they are moved on to their final predetermined destination. In normal routing situations, when multiple packets contend for a single outgoing channel, packets that are not buffered are dropped to avoid congestion. But in hot potato routing, each packet that is routed is constantly transferred until it reaches its final destination because the individual communication links cannot support more than one packet at a time. The packet is bounced around like a “hot potato,” sometimes moving further away from its destination because it has to keep moving through the network. This technique allows multiple packets to reach their destinations without being dropped.

Hot standby
A method of redundancy in which the primary and secondary (backup) systems run simultaneously. The data is mirrored to the secondary server in real time so that both systems contain identical information.

Ghost imaging
Using ghosting software, a method of converting the contents of a hard drive—including its configuration settings and applications—into an image, and then storing the image on a server or burning it onto a CD. When contents of the hard drive are needed again, ghosting software converts the image back to original form. Companies often use ghost imaging when they want to create identical configurations and install the same software on numerous machines.

Gigabyte
2 to the 30th power (1,073,741,824) bytes. One gigabyte is equal to 1,024 megabytes. Gigabyte is often abbreviated as G or GB.

Giant magnetoresistive
Giant magnetoresistive (GMR) is a hard disk drive storage technology. The technology is named for the giant magnetoresistive effect, first discovered in the late 1980s. While working with large magnetic fields and thin layers of magnetic materials, researchers noticed very large resistance changes when these materials were subjected to magnetic fields. Disk drives that are based on GMR head technology use these properties to help control a sensor that responds to very small rotations on the disk. The magnetic rotation yields a very large change in sensor resistance, which in turn provides a signal that can be picked up by the electric circuits in the drive.

Failback
After a failback event, the restoration of a failed system component’s share of a load to a replacement component. When a failed controller in a redundant configuration is replaced, the devices that were originally controlled by the failed controller are usually failed back to the replacement controller to restore the I/O balance, and to restore failure tolerance. Similarly, when a defective fan or power supply is replaced, its load, previously borne by a redundant component, can be failed back to the replacement part.

Failover
The automatic substitution of a functionally equivalent system component for a failed one. Failover most often involves intelligent controllers connected to the same storage devices and host computers. If one of the controllers fails, failover occurs, and the survivor takes over its I/O load.

Fibre Channel ATA
Fibre Channel ATA (FATA) is a hybrid hard drive first introduced by HP in 2004 that combines both Fibre Channel and ATA technologies. FATA drives use an ATA drive mechanism, offering the same performance and capacity as a standard ATA drive, but also feature a Fibre Channel connector, which enables the FATA drive to be used where conventional Fibre Channel drives are currently connected.

File server
A computer with the primary purpose of serving files to clients. A file server may be a general purpose computer that is capable of hosting additional applications or a special purpose computer capable only of serving files.

Popular data backup media:  Magnetic tape, Hard disk, Optical storage, Floppy disk, Solid state storage, Remote backup service…

Ecosystem
A cohesive, robust, interconnected whole. The EVault cloud-connected ecosystem is built on a shared technology platform, leveraged in every deployment—software, appliances, software as a service (SaaS), and managed services—that creates a seamlessly integrated, cloud-connected data protection ecosystem.

Edge computing
A topological paradigm in which applications, data, and computing power (services) are pushed away from centralized points to the logical extremes of a network. Edge computing replicates fragments of information across distributed networks of web servers, which may be vast and include many networks. Edge computing is also referred to as mesh computing, peer-to-peer computing, autonomic (self-healing) computing, grid computing, and other names implying non-centralized, nodeless availability.

Emergency power off
Also referred to as an EPO switch, emergency power off (EPO) is a button or switch that shuts down the power in a room or network of electrical circuits. Typically used in data centers with a large number of computers using large amounts of electricity, the EPO is meant to be activated by a human only in emergency situations when it is necessary to cut the power if human life is in jeopardy or if there is the potential for major damage to the building or equipment (for example, in the case of a fire or electrocution). The sudden loss of power will inevitably lead to the loss of some data, and the EPO is not meant to be used under normal circumstances.

Electron-trapping optical memory
A method of erasable optical storage. Information is written, or stored, by a low-power laser tuned to a specific frequency. The laser elevates the energy level of electrons to a trapped state. The data is read by a second laser that returns the elevated electrons to their ground state.

Encryption
The conversion of plaintext to encrypted text with the intent that it only be accessible to authorized users who have the appropriate decryption key.

Enhanced capacity cartridge system
In data storage technology, enhanced capacity cartridge system (ECCST) is a double length tape cartridge with a nominal uncompressed capacity of approximately 800 Mbytes.

Enterprise content management
Enterprise content management (ECM) describes the technologies used by organizations to capture, manage, store, and control enterprise-wide content, including documents, images, e-mail messages, instant messages, video, and more. ECM software is used to assist in content control associated with business processes, and can be used to assure compliance with regulations (such as Sarbanes-Oxley , HIPPA, and others). ECM has emerged from the convergence of many related technologies such as document management, web content management, and collaboration.

Equipment footprint
The physical area that is occupied only by data center equipment. This area does not include aisles between racks or any space left at end of equipment rows.

Enterprise storage
A centralized storage system used by a large business or organization to manage data. Enterprise storage also indicates processes for data sharing and connectivity. Enterprise storage is different from consumer or home computer storage in terms of the size of the storage system, the amount of data handled by the system, the number of users accessing the system, and also the technology used to create the storage system. Enterprise storage systems usually focus on providing the networking and management operations for data storage, backup, disaster recovery, and archiving.

In Information Technology, a backup or the process of backing up refers to making copies of data so that these additional copies may be used to restore the original after a data loss event. The verb form is back up in two words, whereas the noun is backup (often used like an adjective in compound nouns).

CE-ATA
An interface standard for the connection of storage devices and hosts in consumer electronic devices such as mobile and handheld devices. One of the primary goals of the standard is to standardize connections for small form factor hard disk drives such as one-inch microdrives. The standard is maintained by CE-ATA Workgroup.

Chiller
Also called a data center chiller, a chiller is a cooling infrastructure used in a data centers and industrial facilities. A chiller cooling system removes heat from one element and deposits it into another element. In large data centers, the chiller is used to cool the water used in heating, ventilation, and air-conditioning units. Due to the amount of heat produced by many servers and systems in a data center, chiller cooling systems are operational around-the-clock. As such, a large percentage of the electricity consumed in a data center is used by the chiller.

Cloud storage
The delivery over a network of appropriately configured virtual storage and related data services. Typically, cloud storage hides limits to scalability, is either self-provisioned or provisionless, and is billed based on consumption.

Cloud-connected storage solutions
Next-generation data protection deployed in seamless combination—on-premise and cloud, licensed software and hosted services—to optimize performance, availability, and affordability.

COLD
Acronym for computer output to laser disk. The storage of data on optical disk, such as CD-ROMs. Storing large volumes of data on laser disk, as opposed to microfiche or microfilm, lets the user access and search for this information on a computer, avoid the duplication and security costs of protecting physical documents or film, and more readily distribute information.

Cold standby
A method of redundancy in which the secondary (backup) system is only called upon when the primary system fails. The system on cold standby receives scheduled data backups, but less frequently than a warm standby. Cold standby systems are used for non-critical applications or in cases where data is changed infrequently.

CompactFlash (CF)
Often referred to as a CompactFlash or CF card, CompactFlash is a very small removable mass storage device that relies on flash memory technology, a storage technology that does not require a battery to retain data indefinitely. CompactFlash cards can support 3.3V and 5V operation and can switch between the two, in contrast to other small-form factor flash memory cards that can only operate at one voltage. CompactFlash applications include PDAs, cellular phones, digital cameras, and photo printers.

Compliance
The state of being in accordance with a standard, specification, or clearly defined requirements, including legal requirements. In IT, the "compliance market" is centered around storage and systems that support the retention and discovery of data as required by law or regulation.

Compound document
An electronic document comprising more than one type of file. For example, a text file and image file.

Compressed sensing
An alternative theory to Nyquist’s Law that indicates signals and images can be reconstructed from fewer measurements than what is usually considered necessary. In contrast, Nyquist’s Law states that a signal must be sampled at least twice its highest analog frequency in order to extract all of the information. Also called compressive sampling.

Compression
The process of encoding data to reduce its size. Lossy compression (compression using a technique in which a portion of the original information is lost) is acceptable for some forms of data (for example, digital images) in some applications. However, for most IT applications, lossless compression (compression using a technique that preserves the entire content of the original data, and from which the original data can be reconstructed exactly) is required.

Compressed footprint
Amount of space consumed after compression has been applied to the data set. In a backup solution, compressed footprint refers to the amount of space being utilized by the backed-up data.

Content-addressed storage
Content-addressed storage (CAS) is an object-oriented system for storing data that is not intended to be changed once it is stored (for example, medical images, sales invoices, and archived e-mail). CAS assigns a unique identifying logical address to the data record when it is stored. That address is neither duplicated nor changed in order to ensure that the record always contains the exact same data that was originally stored. CAS relies on disk storage instead of removable media, such as tape.

Continuous data protection
Also called continuous backup, continuous data protection (CDP) refers to backing up computer data by saving as an automated function a copy every time changes are made to that data. It allows users to restore files that are corrupted or that have been accidentally deleted back to any point in time before they were lost.

Cumulative incremental backup
The backup of all data files that have been modified since the last backup.