Task 15: Plan A Multi-Switch Fabric (Optional) - HP StorageWorks 64 - SAN Director Switch Planning Manual

Task 15: Plan a Multi-Switch Fabric (Optional)

If a multi-switch fabric topology is to be implemented, carefully plan the physical
characteristics and performance objectives of the topology. Include the proposed
number of fabric elements, characteristics of attached devices, cost, nondisruptive
growth requirements, and service requirements.
When two or more fabric elements are connected through ISLs to form a fabric,
the elements must have compatible operating parameters, compatible name server
zoning configurations, and unique domain identifications (IDs). Planning for a
fabric must be carefully coordinated with planning for zoned configurations.
Consider the following factors when planning for a multi-switch fabric:
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Planning and implementing a multi-switch fabric is a complex and difficult task.
HP recommends you obtain planning assistance from our professional services
organization before implementing a fabric topology.
SAN High Availability Planning Guide
Fabric topology limits — Consider the practical number of fabric elements
(theoretical maximum of 31, practical limit of 24), number of ISLs per
element, hop count (maximum of 3), and distance limitations (limited by port
type and cable availability).
Bandwidth — Consider using multiple ISLs to increase the total bandwidth
available between two fabric elements.
Load balancing — If heavy traffic between devices is expected, consider
installing multiple ISLs to create multiple minimum-hop paths for load
balancing
Principal switch selection — If required, plan which fabric element is to be
assigned principal switch duties for the fabric.
Critical operations — Consider routing paths that transfer data for critical
operations directly through one director or switch and not through the fabric.
Configuration Planning Tasks
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