Striped Metadevice (Stripe)

A striped metadevice, or stripe, is a metadevice that arranges data across two or more slices. Striping alternates equally-sized segments of data across two or more slices, forming one logical storage unit. These segments are interleaved round-robin, so that the combined space is made alternately from each slice, in effect, shuffled like a deck of cards.

Sometimes a striped metadevice is called a "stripe." Other times, "stripe" refers to the component blocks of a striped concatenation. "To stripe" means to spread I/O requests across disks by chunking parts of the disks and mapping those chunks to a virtual device (a metadevice). Striping is also classified as RAID level 0, as is concatenation.

While striping and concatenation both are methods of distributing data across disk slices, striping alternates chunks of data across disk slices, while concatenation distributes data "end-to-end" across disk slices.

For sequential I/O operations on a concatenated metadevice, DiskSuite reads all the blocks on the first slice, then all the blocks of the second slice, and so forth.

For sequential I/O operations on a striped metadevice, DiskSuite reads all the blocks in a segment of blocks (called an interlace) on the first slice, then all the blocks in a segment of blocks on the second slice, and so forth.

On both a concatenation and a striped metadevice, all I/O occurs in parallel.