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In computers that use multiple hard disk systems, disk striping is the process of dividing a body of data into blocks and spreading the data blocks across several partitions on several hard disks. Each stripe is the size of the smallest partition. For example, if three partitions are selected with one partition equaling 150megabytes, another 100MB, and the third 50MB, each stripe will be 50 MB in size. It is wise to create the partitions equal in size to prevent wasting disk space. Each stripe created is part of the stripe set. Disk striping is used with redundant array of independent disks (RAID). RAID is a storage system that uses multiple disks to store and distribute data. Up to 32 hard disks can be used with disk striping.
There are two types of disk striping: single user and multi-user. Single user disk striping allows multiple hard disks to simultaneously service multiple I/O requests from a single workstation. Multi-user disk striping allows multiple I/O requests from several workstations to be sent to multiple hard disks. This means that while one hard disk is servicing a request from a workstation, another hard disk is handling a separate request from a different workstation.
Disk striping is used with or without parity. When disk striping is used with parity, an additional stripe that contains the parity information is stored on its own partition and hard disk. If a hard disk fails, a fault tolerance driver makes the lost partition invisible allowing reading and writing operations to continue which provides time to create a new stripe set. Once a hard disk fails, the stripe set is no longer fault tolerant, which means that if one or more hard disks fail after the first one, the stripe set is lost. Disk striping without parity provides no fault tolerance. The disk striping process is used in conjunction with software that lets the user know when a disk has failed. This software also allows the user to define the size of the stripes, the color assigned to the stripe set for recognition and diagnosing, and whether parity was used or not.
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Last updated on: Jun 21, 2005
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