Introduction to RAID : RAID Components and Features : Disk Striping

Disk Striping

Disk striping lets you write data across multiple drives instead of just one drive. Disk striping partitions each drive storage space into stripes that can vary in size from 8 KB to 1024 KB. These stripes are interleaved in a repeated sequential manner. The combined storage space contains stripes from each drive. It is recommended that you keep stripe sizes the same across RAID drive groups.

For example, in a four-disk system that uses only disk striping (used in RAID level 0), segment 1 is written to disk 1, segment 2 is written to disk 2, and so on. Disk striping enhances performance because multiple drives are accessed simultaneously, but does not provide data redundancy.

The following figure shows an example of disk striping.

Figure 7. Example of Disk Striping (RAID 0)

Stripe Width

Stripe width is the number of drives involved in a drive group where striping is implemented. For example, a four-disk drive group with disk striping has a stripe width of four.

Stripe Size

The stripe size is the length of the interleaved data segments that the controller writes across multiple drives, excluding parity drives. For example, consider a stripe that contains 64 KB of disk space and has 16 KB of data residing on each disk in the stripe. In this case, the stripe size is 64 KB, and the strip size is 16 KB.

Strip Size

The strip size is the portion of a stripe that resides on a single drive.