Fabric Topology Design Considerations; Large Fabric Design Implications - HP 316095-B21 - StorageWorks Edge Switch 2/24 Planning Manual

Fabric Topology Design Considerations

This section discusses additional fabric topology design considerations, including:

Large Fabric Design Implications

Businesses are experiencing an unprecedented growth of information and the
requirement to maintain that information online. To meet these requirements,
Fibre Channel SANs provide the infrastructure to connect thousands of servers to
hundreds of storage devices. To provide enterprise-class SAN performance and
scalability, large fabric designs are required.
When multiple directors or switches are connected, ISL (E_Port) communication
must be established between fabric elements and the fabric must be initialized.
During fabric initialization, the fabric elements:
However, fabric initialization is not a serial process. The process executes
concurrently across all ISLs in the fabric, causing a massive flood of Class F
traffic that must be processed to the embedded port of each fabric element within
a specified (fabric-wide) error detect time-out value (E_D_TOV). If the fabric
consists of a large number of elements (and therefore ISLs), Class F traffic may
not be processed within the E_D_TOV, resulting in error recovery operations,
time-outs, segmented links, or fabric failure.
SAN High Availability Planning Guide
Large Fabric Design Implications
FCP and FICON in a Single Fabric
Multiple Data Transmission Speeds in a Single Fabric
Fibre Channel Distance Extension
Establish the operating mode for connected E_Port pairs and exchange link
parameters (E_Port names, timeout values, class-specific information, and
flow control parameters).
Exchange fabric parameters, select a principal switch, and assign domain IDs
to all switches.
Employ a routing protocol to establish the shortest path through the fabric and
program route tables for each fabric element.
Exchange the active zone set to ensure uniform zoning is enforced between all
fabric elements.
Planning Considerations for Fibre Channel Topologies
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