Storage Technology Definitions
This glossary explains the meaning of key words and phrases that information technology (IT) and business professionals use when discussing storage and related software products. You can find additional definitions by visiting WhatIs.com or using the search box below.
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3.5" SSD (3.5 solid-state drive)
A 3.5 solid-state drive (SSD) is a data storage device designed for the 3.5-inch hard disk drive (HDD) form factor. It fits into the drive slot as a same-sized HDD in a portable computer, enterprise server, or storage system.
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3D NAND flash
3D NAND is a type of non-volatile flash memory in which the memory cells are stacked vertically in multiple layers.
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3D XPoint
3D XPoint is memory storage technology jointly developed by Intel and Micron Technology Inc. The two vendors have described this new technology as filling a gap in the storage market between dynamic RAM (DRAM) and NAND flash.
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A
address space
Address space is the amount of memory allocated for all possible addresses for a computational entity -- for example, a device, a file, a server or a networked computer.
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AHCI (Advanced Host Controller Interface)
Advanced Host Controller Interface, or AHCI, is a technical standard for an interface that enables software to communicate with Serial ATA (SATA) devices.
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all-flash array (AFA)
An all-flash array (AFA), also known as a solid-state storage disk system or a solid-state array, is an external storage array that supports only flash media for persistent storage.
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application-aware storage
Application-aware storage is a storage system with built-in intelligence about relevant applications and their utilization patterns.
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archive
An archive is a collection of data moved to a repository for long-term retention, to be kept separate for compliance reasons or moved off primary storage media.
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areal density
Areal density measures the amount of data that can be stored on a given amount of physical space on a disk drive.
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B
bad block
A bad block is an area of storage media that is no longer reliable for storing and retrieving data because it has been physically damaged or corrupted.
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bare-metal cloud
Bare-metal cloud is a public cloud service that offers dedicated hardware resources without any installed operating systems or virtualization infrastructure.
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bare-metal restore
A bare-metal restore (also referred to as bare-metal recovery or bare-metal backup) is a data recovery and restoration process where a computer is restored to a new machine, typically after a catastrophic failure.
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big data storage
Big data storage is a compute-and-storage architecture that collects and manages large data sets and enables real-time data analytics.
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bit rot
Bit rot is the slow deterioration in the performance and integrity of data stored on storage media. It is also known by the names bit decay, data rot, data decay and silent corruption.
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block storage
Block storage is an approach to data storage in which each volume acts as an individual hard drive that is configured by the administrator.
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blockchain storage
Blockchain storage is a way of saving data in a decentralized network, which utilizes the unused hard disk space of users across the world to store files.
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brontobyte
A brontobyte is an unofficial measure of memory or data storage that is equal to 10 to the 27th power of bytes.
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business impact analysis (BIA)
A business impact analysis (BIA) is a systematic process to determine and evaluate the potential effects of an interruption to critical business operations as a result of a disaster, accident or emergency.
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byte
In most computer systems, a byte is a unit of data that is eight binary digits long.
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C
cache
A cache -- pronounced CASH -- is hardware or software that is used to store something, usually data, temporarily in a computing environment.
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cache memory
Cache memory, also called CPU memory, is high-speed static random access memory (SRAM) that a computer microprocessor can access more quickly than it can access regular random access memory (RAM).
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capacity management
Capacity management is the broad term describing a variety of IT monitoring, administration and planning actions that ensure that a computing infrastructure has adequate resources to handle current data processing requirements, as well as the capacity to accommodate future loads.
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Ceph
Ceph is open source software providing scalable object-, block- and file-based storage under a unified system. Red Hat and SUSE sell commercially supported versions of Ceph.
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charge-coupled device
A charge-coupled device (CCD) is a light-sensitive integrated circuit that captures images by converting photons to electrons.
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CIFS (Common Internet File System)
CIFS (Common Internet File System) is a protocol that gained popularity around the year 2000, as vendors worked to establish an Internet Protocol-based file-sharing protocol.
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cloud archive
A cloud archive is storage as a service for long-term data retention.
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cloud controller
A cloud controller is a device that moves data between on-premises storage and the cloud.
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cloud data management
Cloud data management is a way to manage data across cloud platforms, either with or instead of on-premises storage.
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Cloud Data Management Interface (CDMI)
The Cloud Data Management Interface (CDMI) is an international standard that defines a functional interface that applications use to create, retrieve, update and delete data elements from cloud storage.
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cloud encryption (cloud storage encryption)
Cloud encryption is a service offered by cloud storage providers whereby a customer's data is transformed using encryption algorithms into ciphertext and stored in the cloud.
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cloud file syncing
Cloud file syncing is an application that updates files held in different locations through the cloud.
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cloud hosting
Cloud hosting is the process of outsourcing an organization's computing and storage resources to a service provider that offers its infrastructure services in a utility model.
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cloud NAS (cloud network attached storage)
Cloud NAS (network attached storage) is remote storage that is accessed over the internet as if it is local.
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cloud object storage
Cloud object storage is a format for storing unstructured data in the cloud. Object storage is considered a good fit for the cloud because it is elastic, flexible and it can more easily scale into multiple petabytes to support unlimited data growth.
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cloud SLA (cloud service-level agreement)
A cloud SLA (cloud service-level agreement) is an agreement between a cloud service provider and a customer that ensures a minimum level of service is maintained.
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cloud storage
Cloud storage is a service model in which data is transmitted and stored on remote storage systems, where it is maintained, managed, backed up and made available to users over a network (typically the internet).
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cloud storage API
A cloud storage API is an application programming interface that connects a locally based application to a cloud-based storage system so that a user can send data to it and access and work with data stored in it.
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cloud storage infrastructure
Cloud storage infrastructure is the hardware and software framework that supports the computing requirements of a private or public cloud storage service.
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cloud storage provider
A cloud storage provider, sometimes referred to as a managed service provider, is a company that offers organizations and individuals the ability to place and retain data in an off-site storage system.
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cloud storage service
A cloud storage service is a business that maintains and manages its customers' data and makes that data accessible over a network, usually the internet.
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cloud testing
Cloud testing is the process of using the cloud computing resources of a third-party service provider to test software applications.
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cloud washing
Cloud washing (also spelled cloudwashing) is the purposeful and sometimes deceptive attempt by a vendor to rebrand an old product or service by associating the buzzword 'cloud' with it.
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clustered file system (CFS)
Clustered file systems are file systems that run on multiple storage servers and can be accessed and managed as a single system.
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clustered network-attached storage (NAS) system
A clustered network-attached storage (NAS) system is a scale-out storage platform made up of multiple NAS nodes networked together into a single cluster.
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cold storage
Cold storage is a computer system or mode of operation designed for the retention of inactive data.
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Common Information Model (CIM)
The Common Information Model (CIM) is a computer industry standard that defines device and application characteristics so system administrators and management programs can control devices and applications from different manufacturers.
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compact disc (CD)
A compact disc is a portable storage medium that can record, store and play back audio, video and other data in digital form.
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CompactFlash card (CF card)
A CompactFlash card (CF card) is a memory card format developed by SanDisk in 1994 that uses flash memory technology to store data on a very small portable device.
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computational storage
Computational storage is an information technology (IT) architecture in which data is processed at the storage device level to reduce the amount of data that has to move between the storage plane and the compute plane.
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content-addressed storage (CAS)
Content-addressed storage (CAS) -- also called content-addressable storage -- is a method for storing fixed content as objects and providing fast access to that content.
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continuous data protection (CDP)
Continuous data protection (CDP), also known as continuous backup, is a backup and recovery storage system in which all the data in an enterprise is backed up whenever any change is made.
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converged network adapter (CNA)
A converged network adapter (CNA) is a single network interface device that provides the functionality of both a Fibre Channel (FC) host bus adapter (HBA) and a TCP/IP Ethernet network interface card (NIC).
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copy data management (CDM)
Copy data management (CDM) is an approach to reducing storage consumption that involves eliminating the unnecessary duplication of production data.
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OpenStack Block Storage (Cinder)
OpenStack Block Storage (Cinder) is open source software designed to create and manage a service that provides persistent data storage to cloud computing applications.
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D
data at rest
Data at rest is a term that is sometimes used to refer to all data in computer storage while excluding data that is traversing a network or temporarily residing in computer memory to be read or updated.
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data availability
Data availability is a term used by computer storage manufacturers and storage service providers to describe how data should be available at a required level of performance in situations ranging from normal through disastrous.
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data compression
Data compression is a reduction in the number of bits needed to represent data.
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data deduplication
Data deduplication is a process that eliminates redundant copies of data and reduces storage overhead.
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data destruction
Data destruction is the process of destroying data stored on tapes, hard disks and other forms of electronic media so that it is completely unreadable and cannot be accessed or used for unauthorized purposes.
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Data Dynamics StorageX
Data Dynamics StorageX is a software suite that specializes in data migration and Microsoft Distributed File System management.
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data lifecycle management (DLM)
Data lifecycle management (DLM) is a policy-based approach to managing the flow of an information system's data throughout its lifecycle: from creation and initial storage to when it becomes obsolete and is deleted.
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data management platform (DMP)
A data management platform (DMP), also referred to as a unified data management platform (UDMP), is a centralized system for collecting and analyzing large sets of data originating from disparate sources.
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data migration
Data migration is the process of transferring data between data storage systems, data formats or computer systems.
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dedicated cloud
A dedicated cloud is a single-tenant cloud infrastructure, which essentially acts as an isolated, single-tenant public cloud.
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DIMM (dual in-line memory module)
DIMM (dual in-line memory module) is a type of computer memory that is natively 64 bits, enabling fast data transfer.
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direct access
In computer storage, direct access is the process of reading and writing data on a storage device by going directly to where the data is physically located on the device rather than having to move sequentially from one physical location to the next to find the correct data.
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direct access storage device (DASD)
A direct access storage device (DASD) is a type of secondary storage device that supports direct access to the stored data, as opposed to sequential access, which is slower and less efficient.
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direct-attached storage (DAS)
Direct-attached storage (DAS) is a type of storage that is attached directly to a computer without going through a network.
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disk array
A disk array, also called a storage array, is a data storage system used for block-based storage, file-based storage or object storage.
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disk mirroring (RAID 1)
Disk mirroring, also known as RAID 1, is the replication of data to two or more disks.
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distributed file system (DFS)
A distributed file system (DFS) is a file system that enables clients to access file storage from multiple hosts through a computer network as if the user was accessing local storage.
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DRAM (dynamic random access memory)
Dynamic random access memory (DRAM) is a type of semiconductor memory that is typically used for the data or program code needed by a computer processor to function.
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E
email archiving
Email archiving is a systematic approach to saving and protecting the data contained in emails to enable fast retrieval.
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eMMC (embedded MultiMediaCard)
An embedded MultiMediaCard (eMMC) is a small storage device made up of NAND flash memory and a simple storage controller.
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enterprise SSD (enterprise solid-state drive)
An enterprise SSD (also known as an enterprise solid-state drive or enterprise solid-state disk) stores data persistently or caches data temporarily in nonvolatile memory and generally provides higher performance and greater endurance than consumer or client SSDs.
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enterprise storage
Enterprise storage is a centralized repository for business information that provides common data management, protection and data sharing functions through connections to computer systems.
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erasure coding
Erasure coding (EC) is a method of data protection in which data is broken into fragments, expanded and encoded with redundant data pieces and stored across a set of different locations or storage media.
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exabyte (EB)
An exabyte (EB) is a large unit of computer data storage, two to the sixtieth power bytes.
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exbibyte (EiB)
An exbibyte (EiB) is a unit that measures data capacity.
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external storage device
An external storage device, also referred to as auxiliary storage and secondary storage, is a device that contains all the addressable data storage that is not inside a computer's main storage or memory.
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F
failover
Failover is a backup operational mode in which the functions of a system component are assumed by a secondary component when the primary becomes unavailable.
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FCoE (Fibre Channel over Ethernet)
FCoE (Fibre Channel over Ethernet) is a storage protocol that enable Fibre Channel (FC) communications to run directly over Ethernet.
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Fibre Channel
Fibre Channel is a high-speed networking technology primarily used for transmitting data among data centers, computer servers, switches and storage at data rates of up to 128 Gbps.
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Fibre Channel (FC) port types
A Fibre Channel port is a hardware pathway into and out of a node that performs data communications over an FC link.
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Fibre Channel switch (FC switch)
A Fibre Channel (FC) switch is a networking device that's compatible with the FC protocol and designed for use in a dedicated storage area network (SAN).
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file storage
File storage stores data in a hierarchical structure, usually in a NAS system. The system storing data and the client retrieving data see files and folders in the same format.
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file synchronization (file sync)
File synchronization, often used as a form of backup, is the process by which files residing in more than one physical location are kept up to date.
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file system
In a computer, a file system -- sometimes written filesystem -- is the way in which files are named and where they are placed logically for storage and retrieval.
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FLAPE
FLAPE (flash plus tape) is an approach to tiered storage that allows administrators to archive data as soon as it is written.
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flash controller (flash memory controller)
A flash controller is the part of solid-state flash memory that communicates with the host device and manages the flash file system directory.
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flash file system
Flash file systems are designed specifically for memory devices. A well-designed flash device and flash file system ensure flash-based capabilities are used efficiently.
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flash memory
Flash memory, also known as flash storage, is a type of nonvolatile memory that erases data in units called blocks and rewrites data at the byte level.
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flash memory card
A flash memory card -- sometimes called a storage card -- is a small storage device that uses non-volatile semiconductor memory to store data on portable or remote computing devices.
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flash solid-state drive (SSD)
A flash solid-state drive (SSD) is a non-volatile storage device that stores persistent data in flash memory.
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flash storage
Flash storage is any type of drive, repository or system that uses flash memory to write and store data for an extended period.
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floating gate transistor (FGT)
A floating gate transistor (FGT) is a complementary metal-oxide semiconductor (CMOS) technology capable of holding an electrical charge in a memory device that is used to store data.
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FreeNAS Project
The FreeNAS storage operating system is compatible with most major protocols and storage hardware and provides file sharing in a NAS environment.
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G
garbage collection (GC)
Garbage collection (GC) is a memory recovery feature built into programming languages such as C# and Java.
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gibibyte (GiB)
A gibibyte (GiB) is a unit of measure of capacity in computing.
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gigabyte (GB)
A gigabyte (GB) -- pronounced with two hard Gs -- is a unit of data storage capacity that is roughly equivalent to 1 billion bytes.