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Non-RAID Drive Architectures
The most widespread standard for configuring multiple hard disk drives is RAID (redundant array of inexpensive/independent disks), which comes in a number of standard configurations and non-standard configurations. Non-RAID drive architectures also exist, and are referred to by acronyms with tongue-in-cheek similarity to RAID: * JBOD (just a bunch of disks): described multiple hard disk drives operated as individual independent hard disk drives. * SPAN or BIG: A method of combining the free space on multiple hard disk drives from "JBoD" to create a spanned volume. Such a concatenation is sometimes also called BIG/SPAN. A SPAN or BIG is generally a spanned volume only, as it often contains mismatched types and sizes of hard disk drives. * MAID (massive array of idle drives): an architecture using hundreds to thousands of hard disk drives for providing nearline storage of data, primarily designed for write once, read occasionally (WORO) applications, in which increased storage den ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hard Disk Drive
A hard disk drive (HDD), hard disk, hard drive, or fixed disk is an electro-mechanical data storage device that stores and retrieves digital data using magnetic storage with one or more rigid rapidly rotating hard disk drive platter, platters coated with magnetic material. The platters are paired with disk read-and-write head, magnetic heads, usually arranged on a moving actuator arm, which read and write data to the platter surfaces. Data is accessed in a random-access manner, meaning that individual Block (data storage), blocks of data can be stored and retrieved in any order. HDDs are a type of non-volatile storage, retaining stored data when powered off. Modern HDDs are typically in the form of a small disk enclosure, rectangular box. Hard disk drives were introduced by IBM in 1956, and were the dominant secondary storage device for History of general-purpose CPUs, general-purpose computers beginning in the early 1960s. HDDs maintained this position into the modern er ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Concatenation
In formal language theory and computer programming, string concatenation is the operation of joining character strings end-to-end. For example, the concatenation of "snow" and "ball" is "snowball". In certain formalizations of concatenation theory, also called string theory, string concatenation is a primitive notion. Syntax In many programming languages, string concatenation is a binary infix operator, and in some it is written without an operator. This is implemented in different ways: * Overloading the plus sign + Example from C#: "Hello, " + "World" has the value "Hello, World". * Dedicated operator, such as . in PHP, & in Visual Basic, and , , in SQL. This has the advantage over reusing + that it allows implicit type conversion to string. * string literal concatenation, which means that adjacent strings are concatenated without any operator. Example from C: "Hello, " "World" has the value "Hello, World". In many scientific publications or standards the con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standard RAID Levels
In computer storage, the standard RAID levels comprise a basic set of RAID ("redundant array of independent disks" or "redundant array of inexpensive disks") configurations that employ the techniques of striping, mirroring, or parity to create large reliable data stores from multiple general-purpose computer hard disk drives (HDDs). The most common types are RAID 0 (striping), RAID 1 (mirroring) and its variants, RAID 5 (distributed parity), and RAID 6 (dual parity). Multiple RAID levels can also be combined or '' nested'', for instance RAID 10 (striping of mirrors) or RAID 01 (mirroring stripe sets). RAID levels and their associated data formats are standardized by the Storage Networking Industry Association (SNIA) in the Common RAID Disk Drive Format (DDF) standard. The numerical values only serve as identifiers and do not signify performance, reliability, generation, hierarchy, or any other metric. While most RAID levels can provide good protection ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Non-standard RAID Levels
Although all RAID implementations differ from the specification to some extent, some companies and open-source projects have developed non-standard RAID implementations that differ substantially from the standard. Additionally, there are non-RAID drive architectures, providing configurations of multiple hard drives not referred to by RAID acronyms. RAID-DP Row diagonal parity is a scheme where one dedicated disk of parity is in a horizontal "row" like in RAID 4, but the other dedicated parity is calculated from blocks permuted ("diagonal") like in RAID 5 and 6. Alternative terms for "row" and "diagonal" include "dedicated" and "distributed". Invented by NetApp, it is offered as RAID-DP in their ONTAP systems. The technique can be considered RAID 6 in the broad SNIA definition and has the same failure characteristics as RAID 6. The performance penalty of RAID-DP is typically under 2% when compared to a similar RAID 4 configuration. RAID 5E, RAID 5EE, and RAID 6E RAID ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nested RAID Levels
Nested RAID levels, also known as hybrid RAID, combine two or more of the standard RAID levels (where "RAID" stands for "redundant array of independent disks" or "redundant array of inexpensive disks") to gain performance, additional redundancy or both, as a result of combining properties of different standard RAID layouts. Nested RAID levels are usually numbered using a series of numbers, where the most commonly used levels use two numbers. The first number in the numeric designation denotes the lowest RAID level in the "stack", while the rightmost one denotes the highest layered RAID level; for example, RAID 50 layers the data striping of RAID 0 on top of the distributed parity of RAID 5. Nested RAID levels include RAID 01, RAID 10, RAID 100, RAID 50 and RAID 60, which all combine data striping with other RAID techniques; as a result of the layering scheme, RAID 01 and RAID 10 represent significantly different nested RAID levels ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
File-based Replication
Replication in computing refers to maintaining multiple copies of data, processes, or resources to ensure consistency across redundant components. This fundamental technique spans databases, file systems, and distributed systems, serving to improve availability, fault-tolerance, accessibility, and performance. Through replication, systems can continue operating when components fail (failover), serve requests from geographically distributed locations, and balance load across multiple machines. The challenge lies in maintaining consistency between replicas while managing the fundamental tradeoffs between data consistency, system availability, and network partition tolerance – constraints known as the CAP theorem. Terminology Replication in computing can refer to: * ''Data replication'', where the same data is stored on multiple storage devices * ''Computation replication'', where the same computing task is executed many times. Computational tasks may be: ** ''Replicated in sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hierarchical Storage Management
Hierarchical storage management (HSM), also known as tiered storage, is a Computer data storage, data storage and data management technique that automatically moves data between high-cost and low-cost data storage media, storage media. HSM systems exist because high-speed storage devices, such as solid-state drive arrays, are more expensive (per byte stored) than slower devices, such as hard disk drives, 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. 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 fast devices. HSM may also be used where more robust storage is available for long-term archiving, but this is slo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tape Library
Tape or Tapes may refer to: Material Tape is long, narrow, thin strip of material usually used to stick things together. (see also Ribbon (other): Adhesive tapes * Adhesive tape, any of many varieties of backing materials coated with an adhesive * Athletic tape, pressure-sensitive tape that holds muscles or bones in certain positions * Box-sealing tape, a pressure-sensitive tape used for closing or sealing corrugated fiberboard boxes * Copper tape (or slug tape), adhesive-backed copper tape used to keep slugs and snails out of certain areas * Double-sided tape, any pressure-sensitive tape that is coated with adhesive on both sides * Duct tape, cloth- or scrim-backed pressure-sensitive tape often coated with polyethylene * Elastic therapeutic tape * Electrical tape, a type of pressure-sensitive tape used to insulate electrical wires and other materials that conduct electricity * Filament tape, a pressure-sensitive tape used for several packaging functions * Gaff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laptop
A laptop computer or notebook computer, also known as a laptop or notebook, is a small, portable personal computer (PC). Laptops typically have a Clamshell design, clamshell form factor (design), form factor with a flat-panel computer screen, screen on the inside of the upper lid and an alphanumeric keyboard and pointing device on the inside of the lower lid. Most of the computer's internal hardware is in the lower part, under the keyboard, although many modern laptops have a built-in webcam at the top of the screen, and some even feature a touchscreen display. In most cases, unlike tablet computers which run on mobile operating systems, laptops tend to run on desktop operating systems, which were originally developed for desktop computers. Laptops are used in a variety of settings, such as at work (especially on business trips), in education, for PC game, playing games, Content creation, content creating, web browser, web browsing, for personal multimedia, and for general P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Throughput
Network throughput (or just throughput, when in context) refers to the rate of message delivery over a communication channel in a communication network, such as Ethernet or packet radio. The data that these messages contain may be delivered over physical or logical links, or through network nodes. Throughput is usually measured in bits per second (, sometimes abbreviated bps), and sometimes in packets per second ( or pps) or data packets per time slot. The system throughput or aggregate throughput is the sum of the data rates that are delivered over all channels in a network. Throughput represents digital bandwidth consumption. The throughput of a communication system may be affected by various factors, including the limitations of the underlying physical medium, available processing power of the system components, end-user behavior, etc. When taking various protocol overheads into account, the useful rate of the data transfer can be significantly lower than the maximum a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Windows Home Server
Windows Home Server (code-named Quattro) is a home server operating system from Microsoft. It was announced on 7 January 2007 at the Consumer Electronics Show by Bill Gates, released to manufacturing on 16 July 2007 and officially released on 4 November 2007. Windows Home Server was based on Windows Server 2003 R2 and was intended to be a solution for homes with multiple connected PCs to offer file sharing, automated backups, print server, and remote access. It is paired with the Windows Home Server Console—client software accessed from another computer on the network to provide a graphical management interface. Power Pack 1 for Windows Home Server was released on 20 July 2008. Power Pack 2 was released on 24 March 2009 and Power Pack 3 was released on 24 November 2009. Windows Home Server 2011, the next version of this operating system, was released on 6 April 2011. Microsoft confirmed Windows Home Server 2011 to be last release in the Windows Home Server product line ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
JBOD
The most widespread standard for configuring multiple hard disk drives is RAID (redundant array of inexpensive/independent disks), which comes in a number of standard configurations and non-standard configurations. Non-RAID drive architectures also exist, and are referred to by acronyms with tongue-in-cheek similarity to RAID: * JBOD (just a bunch of disks): described multiple hard disk drives operated as individual independent hard disk drives. * SPAN or BIG: A method of combining the free space on multiple hard disk drives from "JBoD" to create a spanned volume. Such a concatenation is sometimes also called BIG/SPAN. A SPAN or BIG is generally a spanned volume only, as it often contains mismatched types and sizes of hard disk drives. * MAID (massive array of idle drives): an architecture using hundreds to thousands of hard disk drives for providing nearline storage of data, primarily designed for write once, read occasionally (WORO) applications, in which increased storage dens ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
