HP StorageWorks MSA 2/8 - SAN Switch User Manual page 28

Setting Up ISL Trunking in a Fabric
Note:
trunking group.
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— The addition of a path that is shorter than existing paths will cause traffic
to be rerouted through that path.
— The addition of a path that is longer than existing paths may not be useful
because the traffic will choose the shorter paths first.
For a core/edge topology: Place trunking-capable switches at the core of the
fabric and switches that are not capable of trunking at the edge of the fabric.
This allows for the maximum amount of trunking between core switches and
preserves the investment in any switches that are not capable of trunking.
For trunking groups over which traffic is likely to increase as business
requirements grow, consider leaving one or two ports in the quad available for
future use as a non-disruptive addition of bandwidth to that trunk.
Consider creating redundant Trunking groups where additional ports are
available or paths are particularly critical. This protects against
oversubscription of an entire trunking group, multiple ISL failures, and the
rare occurrence of an ASIC failure.
To provide the highest level of reliability, deploy trunking groups in redundant
fabrics to further ensure ISL failures do not disrupt business operations.
SWL and LWL fiber optic cables and transceivers can be used in the same
ISL Trunking Version 3.1.x/4.1.x User Guide