Global Information Lookup Global Information

Parity drive information


A parity drive is a hard drive used in a RAID array to provide fault tolerance. For example, RAID 3 uses a parity drive to create a system that is both fault tolerant and, because of data striping, fast.[1] Basically, a single data bit is added to the end of a data block to ensure the number of bits in the message is either odd or even.[2]

One way to implement a parity drive in a RAID array is to use the exclusive or, or XOR, function. XOR is a Boolean logic function which means 'one or the other, but not both'. The XOR of all of the data drives in the RAID array is written to the parity drive. If one of the data drives fails, the XOR of the remaining drives is identical to the data of the lost drive. Therefore, when a drive is lost, recovering the drive is as simple as copying the XOR of the remaining drives to a fresh data drive.

  1. ^ Definitions of RAID configurations Retrieved on 2010-11-15
  2. ^ "What does the parity bit do in RAID?". ComputerWeekly.com.

and 23 Related for: Parity drive information

Request time (Page generated in 0.8571 seconds.)

Parity drive

Last Update:

A parity drive is a hard drive used in a RAID array to provide fault tolerance. For example, RAID 3 uses a parity drive to create a system that is both...

Word Count : 189

Parity bit

Last Update:

A parity bit, or check bit, is a bit added to a string of binary code. Parity bits are a simple form of error detecting code. Parity bits are generally...

Word Count : 1678

Standard RAID levels

Last Update:

striping, mirroring, or parity to create large reliable data stores from multiple general-purpose computer hard disk drives (HDDs). The most common types...

Word Count : 4543

RAID

Last Update:

Hamming-code parity. All disk spindle rotation is synchronized and data is striped such that each sequential bit is on a different drive. Hamming-code parity is...

Word Count : 7010

Hard disk drive

Last Update:

drives loses 1/n of capacity (which equals to the capacity of a single drive) due to storing parity information. RAID subsystems are multiple drives that...

Word Count : 14062

Tape drive

Last Update:

A tape drive is a data storage device that reads and writes data on a magnetic tape. Magnetic-tape data storage is typically used for offline, archival...

Word Count : 1707

NetApp

Last Update:

therefore, have no dedicated parity drives. DDP compare to traditional RAID groups restores data from lost disk drive to multiple drives which provide a few times...

Word Count : 4561

RAID processing unit

Last Update:

necessary for calculating parity data, and for maintaining data integrity when writing to a disk array that uses a parity drive or data striping. An RPU...

Word Count : 73

Apple Network Server

Last Update:

ANS from the ones on the PM9500, presumably because of added support for parity memory. The ANS memory data lane controllers are 343S1161 instead of 343S1141...

Word Count : 2617

Nested RAID levels

Last Update:

the distributed parity of RAID 5. As a RAID 0 array striped across RAID 5 elements, minimal RAID 50 configuration requires six drives. On the right is...

Word Count : 1690

Parity of zero

Last Update:

spoken articles) In mathematics, zero is an even number. In other words, its parity—the quality of an integer being even or odd—is even. This can be easily...

Word Count : 7477

Parity of esteem

Last Update:

establishing parity of esteem means assigning equal value to mental health care and to physical health care. In many healthcare systems, parity of esteem...

Word Count : 395

Grid parity

Last Update:

Grid parity (or socket parity) occurs when an alternative energy source can generate power at a levelized cost of electricity (LCOE) that is less than...

Word Count : 2712

Point of difference

Last Update:

balance of differentiation and association is required, and a point of parity has to be adopted in order to allow a business to remain or further enhance...

Word Count : 2106

Powertrain

Last Update:

or air. This includes the engine, transmission, drive shafts, differentials, and the final drive (drive wheels, continuous track as in military tanks or...

Word Count : 861

World Long Drive Championship

Last Update:

The Volvik World Long Drive Championship is an annual long drive competition in the sport of golf. It was first held in 1974, and since 2000 has comprised...

Word Count : 1945

Write Anywhere File Layout

Last Update:

RAID 17 data and 3 parity SAS drives 1.8 TB configured as RAID-TEC and second RAID in the master plex is RAID-DP with 2 data and 2 parity SSD 960 GB. The...

Word Count : 3163

Error detection and correction

Last Update:

commonly used in computer networks and storage devices such as hard disk drives. The parity bit can be seen as a special-case 1-bit CRC. The output of a cryptographic...

Word Count : 4200

Basketball

Last Update:

New York Times. Retrieved August 28, 2016) Jeep (July 16, 2012). "Passion Drives Creation – Jeep® & USA Basketball". Archived from the original on July 17...

Word Count : 11916

Brand

Last Update:

all stakeholders, converting simple awareness to strong commitment. Brand parity is the perception of customers that some brands are equivalent. This means...

Word Count : 14740

IBM 727

Last Update:

729-series tape drive. The 727 was withdrawn on May 12, 1971. The tape had seven parallel tracks – six for data and one to maintain parity. Tapes with character...

Word Count : 160

Data corruption

Last Update:

accumulate and overwhelm the number of parity bits. Instead of parity being checked on each read, the parity is checked during a regular scan of the...

Word Count : 2196

NetApp FAS

Last Update:

with 1 dedicated parity disk allowing any 1 drive to fail in a RAID group. RAID-DP with 2 dedicated parity disks allowing any 2 drives to fail simultaneously...

Word Count : 4380

PDF Search Engine © AllGlobal.net