Disk array

Last updated
HP EVA4400 storage array, consisting of 2U controller enclosure (top) and 4 2U disk shelves HP EVA4400-1.jpg
HP EVA4400 storage array, consisting of 2U controller enclosure (top) and 4 2U disk shelves

A disk array is a disk storage system which contains multiple disk drives. [1] It is differentiated from a disk enclosure, in that an array has cache memory and advanced functionality, like RAID, deduplication, encryption and virtualization.

Components of a disk array include: [2]

Typically a disk array provides increased availability, resiliency, and maintainability by using additional redundant components (controllers, power supplies, fans, etc.), often up to the point where all single points of failure (SPOFs) are eliminated from the design. [3] Additionally, disk array components are often hot-swappable.

Traditionally disk arrays were divided into categories: [2]

Primary vendors of storage systems include Coraid, Inc., DataDirect Networks, Dell EMC, Fujitsu, Hewlett Packard Enterprise, Hitachi Data Systems, Huawei, IBM, Infortrend, NetApp, Oracle Corporation, Panasas, Pure Storage and other companies that often act as OEM for the above vendors and do not themselves market the storage components they manufacture. [1]

Related Research Articles

Computer data storage Storage of digital data readable by computers

Computer data storage is a technology consisting of computer components and recording media that are used to retain digital data. It is a core function and fundamental component of computers.

In computing, a file server is a computer attached to a network that provides a location for shared disk access, i.e. storage of computer files that can be accessed by the workstations that are able to reach the computer that shares the access through a computer network. The term server highlights the role of the machine in the traditional client–server scheme, where the clients are the workstations using the storage. A file server does not normally perform computational tasks or run programs on behalf of its client workstations.

RAID is a data storage virtualization technology that combines multiple physical disk drive components into one or more logical units for the purposes of data redundancy, performance improvement, or both. This was in contrast to the previous concept of highly reliable mainframe disk drives referred to as "single large expensive disk" (SLED).

Network-attached storage Computer data storage server

Network-attached storage (NAS) is a file-level computer data storage server connected to a computer network providing data access to a heterogeneous group of clients. NAS is specialized for serving files either by its hardware, software, or configuration. It is often manufactured as a computer appliance – a purpose-built specialized computer. NAS systems are networked appliances that contain one or more storage drives, often arranged into logical, redundant storage containers or RAID. Network-attached storage removes the responsibility of file serving from other servers on the network. They typically provide access to files using network file sharing protocols such as NFS, SMB, or AFP. From the mid-1990s, NAS devices began gaining popularity as a convenient method of sharing files among multiple computers. Potential benefits of dedicated network-attached storage, compared to general-purpose servers also serving files, include faster data access, easier administration, and simple configuration.

A disk array controller is a device that manages the physical disk drives and presents them to the computer as logical units. It almost always implements hardware RAID, thus it is sometimes referred to as RAID controller. It also often provides additional disk cache.

Disk enclosure Specialized casing

A disk enclosure is a specialized casing designed to hold and power disk drives while providing a mechanism to allow them to communicate to one or more separate computers.

A virtual tape library (VTL) is a data storage virtualization technology used typically for backup and recovery purposes. A VTL presents a storage component as tape libraries or tape drives for use with existing backup software.

A NetApp FAS is a computer storage product by NetApp running the ONTAP operating system; the terms ONTAP, AFF, ASA, FAS are often used as synonyms. "Filer" is also used as a synonym although this is not an official name. There are three types of FAS systems: Hybrid, All-Flash, and All SAN Array:

  1. NetApp proprietary custom-build hardware appliances with HDD or SSD drives called hybrid Fabric-Attached Storage
  2. NetApp proprietary custom-build hardware appliances with only SSD drives and optimized ONTAP for low latency called ALL-Flash FAS
  3. All SAN Array build on top of AFF platform, and provide only SAN-based data protocol connectivity.

In computer science, storage virtualization is "the process of presenting a logical view of the physical storage resources to" a host computer system, "treating all storage media in the enterprise as a single pool of storage."

Automated tiered storage is the automated progression or demotion of data across different tiers (types) of storage devices and media. The movement of data takes place in an automated way with the help of a software or embedded firmware and is assigned to the related media according to performance and capacity requirements. More advanced implementations include the ability to define rules and policies that dictate if and when data can be moved between the tiers, and in many cases provides the ability to pin data to tiers permanently or for specific periods of time. Implementations vary, but are classed into two broad categories: pure software based implementations that run on general purpose processors supporting most forms of general purpose storage media and embedded automated tiered storage controlled by firmware as part of a closed embedded storage system such as a SAN disk array. Software Defined Storage architectures commonly include a component of tiered storage as part of their primary functions.

IBM storage

The IBM Storage product portfolio includes disk, flash, tape, NAS storage products, storage software and services. IBM's approach is to focus on data management.

In computing, a page cache, sometimes also called disk cache, is a transparent cache for the pages originating from a secondary storage device such as a hard disk drive (HDD) or a solid-state drive (SSD). The operating system keeps a page cache in otherwise unused portions of the main memory (RAM), resulting in quicker access to the contents of cached pages and overall performance improvements. A page cache is implemented in kernels with the paging memory management, and is mostly transparent to applications.

Dell Compellent

Compellent Technologies, Inc, founded in 2002, was a manufacturer of enterprise computer data storage systems that provided block-level storage resources to small and medium sized IT infrastructures. The company was headquartered in Eden Prairie, Minnesota, USA. Compellent's flagship product, Storage Center, is a storage area network (SAN) system that combines a standards-based hardware platform and a suite of virtualized storage management applications, including automated tiered storage through a proprietary process called "DataProgression", thin provisioning and replication. The company developed software and products aimed at mid-size enterprises and sold through a channel network of independent providers and resellers. It became part of Dell in February 2011.

Universal Storage Platform

Universal Storage Platform (USP) was the brand name for an Hitachi Data Systems line of computer data storage disk arrays circa 2004 to 2010.

This glossary of computer hardware terms is a list of definitions of terms and concepts related to computer hardware, i.e. the physical and structural components of computers, architectural issues, and peripheral devices.

Texas Memory Systems, Inc. (TMS) was an American corporation that designed and manufactured solid-state disks (SSDs) and digital signal processors (DSPs). TMS was founded in 1978 and that same year introduced their first solid-state drive, followed by their first digital signal processor. In 2000 they introduced the RamSan line of SSDs. Based in Houston, Texas, they supply these two product categories to large enterprise and government organizations.

IBM Storwize systems were virtualizing RAID computer data storage systems with raw storage capacities up to 32 PB. Storwize is based on the same software as IBM SAN Volume Controller (SVC).

Converged storage is a storage architecture that combines storage and computing resources into a single entity. This can result in the development of platforms for server centric, storage centric or hybrid workloads where applications and data come together to improve application performance and delivery. The combination of storage and compute differs to the traditional IT model in which computation and storage take place in separate or siloed computer equipment. The traditional model requires discrete provisioning changes, such as upgrades and planned migrations, in the face of server load changes, which are increasingly dynamic with virtualization, where converged storage increases the supply of resources along with new VM demands in parallel.

Dell EMC Unity is one of Dell EMC’s mid-range storage array product lines. It was designed from the ground up as the next generation midrange unified storage array after the EMC VNX and VNXe series, which evolved out of the EMC Clariion SAN disk array.

Dell EMC VMAX is Dell EMC’s flagship enterprise storage array product line. It evolved out of the EMC Symmetrix array, EMC’s primary storage product of 1990s and early 2000s.

References

  1. 1 2 Beal, Vangie. "What is Disk Array Definition? Webopedia Definition". www.webopedia.com. Retrieved 2020-04-07.
  2. 1 2 "What Is a Storage Array? Data Server and Disk Architecture". DNSstuff. 2019-10-10. Retrieved 2020-04-07.
  3. "What is disk array? - Definition from WhatIs.com". SearchStorage. Retrieved 2020-04-07.