Installation manual

Fibre Channel SAN link speed
The recommended Dell/EMC CX Series link speed is 4 Gb/s. In any case, EMC recommends
setting the link speed to auto. If the switch does not support 4 Gb/s, then the Dell/EMC CX
Series SP port will automatically set itself to the lower speed. Currently, the port-speed choices
are auto, 4 Gb/s, 2 Gb/s and 1Gb/s. Set the switch to auto negotiate.
Zoning
EMC strongly recommends World Wide Name (WWN) zoning on all switches in the SANs. EMC
also recommends single initiator zoning.
Port-to-HBA relationships
EMC recommends that each HBA be connected into a different fabric. Connect each SP into both
fabrics. This provides a total of four connections to the Dell/EMC CX Series for each LUN. For a
CX3-80 this kind of connectivity allows 256 highly available hosts attached to the Dell/EMC CX
Series. Additional connections may be added for performance, but this will decrease the number
of hosts attached to the Dell/EMC CX Series. The minimum configuration is one HBA path to
each Dell/EMC CX Series SP for a minimum of two paths to the Dell/EMC CX Series.
Four Dell/EMC CX Series ports should be seen by each host; two ports from SP A and two ports
from SP B.
Fabric connectivity
EMC allows a maximum of three hops between the Dell/EMC CX Series and the host. Minimize
the number of hops whenever possible.
Multipath software
EMC supports several multipath software products. EMC recommends PowerPath for all
Dell/EMC CX Series supported hosts as a best practice.
PowerPath
PowerPath provides failover and load-balancing capability across all the ports configured to the
Dell/EMC CX Series. PowerPath supports a maximum of eight active and eight passive paths to
any Dell/EMC CX Series LUN.
CLAR_Opt is the default load-balancing configuration. Do not change this setting.
Dell/EMC CX Series Initial Configuration
Best Practices Planning 27