Combining mirroring and striping

Mirroring and striping can be used together to achieve a significant improvement in performance when there are multiple I/O streams.

Striping provides better throughput because parallel I/O streams can operate concurrently on separate devices. Serial access is optimized when I/O exactly fits across all stripe units in one stripe.

Because mirroring is generally used to protect against loss of data due to disk failures, it is often applied to write-intensive workloads which degrades throughput. In such cases, combining mirroring with striping delivers both high availability and increased throughput.

A mirrored-stripe volume may be created by striping half of the available disks to form one striped data plex, and striping the remaining disks to form the other striped data plex in the mirror. This is often the best way to configure a set of disks for optimal performance with reasonable reliability. However, the failure of a single disk in one of the plexes makes the entire plex unavailable.

Alternatively, you can arrange equal numbers of disks into separate mirror volumes, and then create a striped plex across these mirror volumes to form a striped-mirror volume.

The failure of a single disk in a mirror does not take the disks in the other mirrors out of use. A striped-mirror layout is preferred over a mirrored-stripe layout for large volumes or large numbers of disks.

More Information

Mirroring plus striping (striped-mirror, RAID-1+0 or RAID-10)