Definition

fan-out ratio

A fan-out ratio is the relationship in quantity between a single port on a storage device and the number of servers that are attached to it.

It is important to know the fan-out ratio in a storage area network (SAN ) design so that each server gets optimal access to storage resources. When the fan-out ratio is high and the storage array becomes overloaded, application performance will be affected negatively. Too low a low fan-out ratio, however, results in an uneconomic use of storage.

Key factors in deciding the optimum fan-out ratio are server host bus adapter (HBA) queue depth, storage device input/output (IOPS) and port throughput.

Contributor(s): Antony Adshead
This was last updated in March 2012
Posted by: Margaret Rouse

Email Alerts

Register now to receive SearchStorage.co.uk-related news, tips and more, delivered to your inbox.
By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy

More News and Tutorials

Do you have something to add to this definition? Let us know.

Send your comments to techterms@whatis.com