Data striping

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In computer data storage, data striping is the segmentation of logically sequential data, such as a single file, so that segments can be assigned to multiple physical devices (usually disk drives in the case of RAID storage, or network interfaces in the case of Grid-oriented Storage) in a round-robin fashion and thus written concurrently.

This technique is useful if the processor is capable of reading or writing data faster than a single disk can supply or accept it. While data is being transferred from the first disk, the second disk can locate the next segment. Striping can be either of type coarse or fine.

Data striping is used in some modern databases, such as Sybase, and in certain RAID devices under software or hardware control, such as IBM's RAMAC array subsystem. File systems of clusters also use striping. Oracle Automatic Storage Management allows asm files to be either coarse or fine striped.

Data striping can also be achieved with Linux's LVM (Logical Volume Management). The LVM system allows for the adjustment of coarseness of the striping pattern. LVM tools will allow implementation of data striping in conjunction with mirroring, however LVM1 will not allow adding additional disks to a striped Logical Volume (LV). This can be achieved with LVM2 using LVM2 format metadata. ^[1]

Data striping is different from mirroring, though they may be used in conjunction.

Advantages include performance and throughput. In some RAID configurations (such as a RAID-5 with a parity drive), if one drive fails and the system crashes, the data can be restored by utilizing the other drives in the array. However, in some RAID configurations (such RAID-0) if one RAID disk fails, this file (and all other data), will be lost, because the file is saved in parts, divided into several disks belonging to the RAID.

This article was originally based on material from the Free On-line Dictionary of Computing, which is licensed under the GFDL.