HP Surestore 64 Planning Guide - Page 71

To provide high availability and load balancing for Fibre Channel traffic through a multiswitch fabric, multiple ISLs should be provided between directors that participate in critical data transfer paths. Multiple Directors Multiple directors can be installed in the enterprise to provide device availability and multiswitch fabric support. • Device availability Spreading connections across multiple directors eliminates each director as a single point of failure. Device availability, port availability, and port serviceability are also increased by using a configuration that has multiple directors (with every device attached to at least two directors). • Multiswitch fabric support The director operational software provides the ability to interconnect directors (through expansion port (E_Port) connections) to form a multiswitch fabric. Up to 16 interconnected directors are supported in a single fabric. Spare Ports Plan to maintain unused (spare) director ports if port connections must be quickly moved and re-established after a failure. If an individual port or an entire FPM card fails, cards can be removed and replaced, spare port connections identified (through the Product Manager application), and fiber-optic cables rerouted and reconnected while the director is operational. Although there is no requirement to provide spare ports, they are recommended to allow quick transfer of connections in case of failure. Installation of at least one spare FPM card is recommended. In addition, unused ports on any FPM card can be used as spare ports. Port Connectivity and Fiber-Optic Cabling 57 Planning Considerations