FCoE Cookbook for HP Virtual Connect Version 4.20 Firmware Enhancements May 2014

29
Considerations
The Nexus switches operate as Fiber Channel Forwarders (FCF). This is the default Cisco Nexus 5xxx Series switches
mode, it’s also called the fabric mode. In this mode, the switch provides standard Fibre Channel switching capability and
features.
In a fully populated c7000 enclosure, the server-to-uplink ratio is 16:1. This configuration can result in poor response
time and sometimes requires particular performance monitoring attention. The use of additional FCoE uplink ports,
both for better performance and better redundancy might be considered.
Multiple VSAN support
Cisco MDS and Nexus switches offer a capability called “Virtual SANs” (VSANs). VSANs allow an enterprise customer to
maintain single physical SAN infrastructure, while providing separation and traffic isolation to the servers based on the
business unit, types of the operating systems or need for logical isolation. But with the use of a single FCoE network in
this scenario, servers can only access to a single VSAN, and therefore all benefits of Virtual SANs capability are here
withdrawn.
SAN Port Channel and Trunking
The use of a SAN Port Channel between the Nexus and MDS core switch is highly recommended to create enough SAN
subscription. F-Port Port Channeling increases the uplink resiliency, optimizes the bandwidth utilization and increases
the aggregated bandwidth with load balancing.
 SAN Port Channel between Nexus and upstream switches is only supported with Cisco switches (MDS or Nexus series).
 E ports that are members of the same SAN Port Channel cannot be connected to different core switches.
Figure 14: Cisco Nexus 5xxx switches operating as FC Forwarder (FCF)
E_Ports
N_Port
VF_Port
VN_Port
Virtual Connect
(FIP Snooping mode)
FCF
Lossless Ethernet
network
Cisco
MDS
FC
Storage
Array
E_Ports
F_Port
Native FC
Dual-Hop FCoE
Nexus 5xxx
Series
(FCF Mode)
SAN
Port Channel
VN_Port
Native FC
FC
Storage
Array
N_Port
F_Port
ISL
Server 2
(ENode)
Server 1
(ENode)
Converged Ethernet/FCoE
FC