Label: Varicocele Records - Cassette 1 • Format: Cassette Compilation, Limited Edition, Numbered C60 • Country: US • Genre: Electronic • Style: Noise, Experimental
In computer storagethe standard RAID levels comprise a basic set of RAID redundant array of independent disks configurations that employ the techniques of stripingmirroringor parity to create large reliable data stores from multiple general-purpose computer hard disk drives HDDs.
For valuable data, RAID is only one building block of a larger data loss prevention and recovery scheme — it cannot replace a backup plan. This configuration is typically implemented having speed as the intended goal. The diagram in this section shows how the data is distributed into A x stripes on two disks, with A1:A2 as the first stripe, A3:A4 as the second one, etc. However, some Raid23 - Various - Needlepoint benchmarks also show a drop in performance for the same comparison.
This configuration offers no parity, striping, or spanning of disk space across multiple disks, since the data is mirrored on all disks belonging to the array, and the array can only be as big as the smallest member disk. This layout is useful when read performance or reliability is more important than write performance or the Raid23 - Various - Needlepoint data storage capacity. The array will continue to operate so long as at least one member drive is operational.
The disks are synchronized by the controller to spin at the same angular orientation they reach index at the same time so it generally cannot service multiple requests simultaneously. This makes it suitable for applications that demand the highest transfer rates in long sequential reads and writes, for example uncompressed video editing.
Applications that make small reads and writes from random disk locations will get the worst performance out of this level. The requirement that all disks spin synchronously in Color Blind - Ice Cube - Death Certificate lockstep added design considerations to a level that provided no significant advantages over other RAID levels, so it quickly became useless and is now obsolete.
In diagram 1, a read request for block A1 would be serviced by disk 0. A simultaneous read request for block B1 would have to wait, but a read request for B2 could be serviced concurrently by disk 1. It requires that all drives but one be present to operate. Upon failure of a single drive, subsequent reads can be calculated from the distributed parity such that no data are lost. Additionally, write performance is increased since all RAID members participate in the serving of write requests.
Since parity calculation is performed on the full stripe, small changes to the array experience write amplification : in the worst case when a single, logical sector is to be written, the original sector and the according parity sector need to be read, the original data is removed from the parity, the new data calculated into the parity and both the new data sector and the new parity sector are written.
Several methods, including dual check data computations parity and Reed-Solomonorthogonal dual parity check data and diagonal parity, have been used to implement RAID Level 6.
When either diagonal or orthogonal dual parity is used, a second parity calculation is necessary for write operations. When a Reed Solomon code is used the second parity calculation is unnecessary. Reed Solomon has the advantage of allowing all redundancy information to be contained within a given stripe.
The second parity value is analogous, but with each data chunk bit-shifted a different amount. We will show we can also recover from simultaneous failure of 2 drives. This Raid23 - Various - Needlepoint only M. Ward - Transistor Radio half as many equations as needed to solve for the missing values.
It is possible to support a far greater number of drives by choosing the parity function more carefully. So High - Sunz Of Soul - The Situation one data chunk is lost, the situation is similar to the one before.
In the case of two lost data chunks, we can compute the recovery formulas algebraically. This can be mitigated with a hardware implementation or by using an FPGA. The following table provides an overview of some considerations for standard RAID levels. In each case:. Combinations of two or more standard RAID levels. From Wikipedia, the free encyclopedia. This section Raid23 - Various - Needlepoint additional citations for verification.
Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. Storage Networking Industry Association. Retrieved ACM Computing Surveys. July 1, April 23, Persgroep Online Services. August 7, November 1, Oracle Corporation. Retrieved 11 December O'Reilly Series illustrated ed. Blueprints for high availability 2, illustrated ed. John Wiley and Sons. McGraw-Hill Professional. Raid23 - Various - Needlepoint Technologies.
University of Massachusetts. Peter May 21, Linux Kernel Organization. Retrieved November 4, Information Sciences and Systems. Redundant array of Raid23 - Various - Needlepoint disks.
Data scrubbing Data striping Disk array controller Disk mirroring Parity drive. Non-RAID drive architectures. Hidden categories: CS1 errors: missing periodical Articles needing additional references from January All articles needing additional references All articles with unsourced statements Articles with unsourced statements Andy Bey Celestial Blues (The Avener Rework) - The Avener - The Wanderings Of The Avener April Namespaces Article Talk.
Block-level striping without parity or mirroring. Bit-level striping with Hamming code for error correction. One drive failure [d].
Softly As In A Morning Sunrise - Rhythmstick - Rhythmstick, Welcome Home (Sanitarium) - Metallica - Master Of Puppets, Imagination - Panorama Sound Orchestra - Dancing In The Dark, Dan Republike - Zabranjeno Pušenje - Male Priče O Pišonji I Žugi