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RAID Levels
A RAID level is any of the possible configurations of a RAID disk array. ''RAID'' stands for ''redundant array of independent disks'' (or, formerly, ''redundant array of inexpensive disks''). RAID levels may refer to: * Standard RAID levels, all the RAID configurations defined in the Common RAID Disk Drive Format standard, which is maintained by the Storage Networking Industry Association * 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 ..., RAID configurations that incorporate features of two or more standard RAID levels * Non-standard RAID levels, variants of standard or nested RAID levels. Non-standard RAID levels deviate from the standard configurations defined by the Storage Networking Industry Association (SNIA). See also * Non-RAID drive architectures { ... [...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] |
RAID
RAID (; redundant array of inexpensive disks or redundant array of independent disks) is a data storage virtualization technology that combines multiple physical Computer data storage, data storage components into one or more logical units for the purposes of data redundancy, performance improvement, or both. This is in contrast to the previous concept of highly reliable mainframe disk drives known as ''single large expensive disk'' (''SLED''). Data is distributed across the drives in one of several ways, referred to as RAID levels, depending on the required level of redundancy (engineering), redundancy and performance. The different schemes, or data distribution layouts, are named by the word "RAID" followed by a number, for example RAID 0 or RAID 1. Each scheme, or RAID level, provides a different balance among the key goals: reliability engineering, reliability, availability, computer performance, performance, and computer data storage#Capacity, capacity. RAID levels ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Disk Array
A disk array is a disk storage system which contains multiple disk drives. It is differentiated from a disk enclosure, in that an array has cache (computing), cache memory and advanced functionality, like redundant array of independent disks, RAID, Data deduplication, deduplication, encryption and Storage virtualization, virtualization. Components of a disk array include: * Disk array controllers * Cache (computing), Cache in form of both volatile random-access memory and Non-volatile memory, non-volatile flash memory. * Disk enclosures for both Magnetic storage, magnetic rotational hard disk drives and electronic solid-state drives. * Power supply, Power supplies 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 point of failure, single points of failure (SPOFs) are eliminated from the design. Additionally, disk array com ... [...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] |
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] |
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] |
