Data Storage

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).