Q-Logic 2-8C manual Multiple Chassis Fabrics, Optimizing Device Performance

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Multiple Chassis Fabrics

3.4

Multiple Chassis Fabrics

By connecting switches together you can expand the number of available ports for devices. Each switch in the fabric is identified by a unique domain ID, and the fabric will automatically resolve domain ID conflicts. Because the Fibre Channel ports are self-configuring, you can connect SANbox2-8c and other FC-SW-2 compliant switches together in a wide variety of topologies.

3.4.1

Optimizing Device Performance

When choosing a topology for a multiple chassis fabric, you should also consider the locality of your server and storage devices and the performance requirements of your application. Storage applications such as video distribution, medical record storage/retrieval or real-time data acquisition can have specific latency or bandwidth requirements. Refer to ”Performance” on page 3-4for information about latency and bandwidth. However, the highest performance is achieved on Fibre Channel switches by keeping traffic within a single switch instead of relying on ISLs. Therefore, for optimal device performance place devices on the same switch under the following conditions:

„Heavy I/O traffic between specific server and storage devices.

„Distinct speed mismatch between devices such as the following:

‰A 2-Gbps server and a slower 1-Gbps storage device

‰A high performance server and slow tape storage device

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