Cisco Nexus 7000 Design Manual page 38

FlexPod Implementation and Design
As shown in
channels (Po13 & Po14). The FCoE port channels only carry only Fibre Channel traffic that is associated
to a VSAN/VLAN set, with the set in turn supported only on one side of the fabric A or B. As in this
example, the vHBA "FABRIC-A" is defined in the service profile. The vHBA uses a virtual circuit, VC
713, to traverse the UCS unified fabric to port channel Po1 where FCoE traffic egresses the Cisco UCS
domain and enters the Cisco Nexus 7000 platform. Fabric A supports a distinct VSAN, which is not
present on Fabric B, thus maintaining fabric isolation.
A balanced and predictable fabric is critical within any data center environment. As designed, the
FlexPod accommodates a myriad of traffic types (vMotion, NFS, FCoE, control traffic, and so on) and
is capable of absorbing traffic spikes and protect against traffic loss. To address these requirements the
Cisco UCS QoS system classes and Cisco Nexus policies should be configured. In this validation effort
the FlexPod was configured to support jumbo frames with an MTU size of 9000. Enabling jumbo frames
allows the FlexPod environment to optimize throughput between devices while simultaneously reducing
the consumption of CPU resources. This class was assigned to the Best-Effort class. Jumbo frames are
important to make sure MTU settings are applied uniformly across the stack to prevent fragmentation
and the negative performance implications due to inconsistent MTUs.
Cisco Unified Computing System – C-Series Server Design
Cisco UCS Manager 2.1 provides two connectivity modes for Cisco UCS C-Series Rack Mount Server
management. The two connectivity modes are as follows:
Dual-wire management (Shared LOM)—This management mode is supported in the Cisco UCS
•
Manager releases earlier than 2.1. Shared LAN on Motherboard (LOM) ports on the rack server are
used exclusively for carrying management traffic. A separate cable connected to one of the ports on
the PCIe card carries the data traffic. Using two separate cables for managing data traffic and
management traffic is referred to as dual-wire management.
• Single-wire management (Sideband)—Cisco UCS Manager release version 2.1 introduces an
additional rack server management mode using Network Controller Sideband Interface (NC-SI).
Cisco UCS VIC 1225 uses the NC-SI, which can carry both data traffic and management traffic on
the same cable. This new feature is referred to as single-wire management and will allow for denser
server to FEX deployments.
The FlexPod Distinct Uplink design is capable of supporting both single and dual wire management. In
Note
the lab both implementations were used but at the time for this CVD the NetApp IMT only supports the
dual-wire option. Make sure to verify single-wire support with your trusted advisors or through the
NetApp IMT tool.
Figure 17
functional perspective the 1 RU Cisco Nexus 2232PP FEX replaces the Cisco UCS 2204 or 2208 FEX
that are located with the Cisco UCS 5108 blade chassis. Each 10 Gigabit Ethernet VIC port connects to
fabric A or B through FEX. The Cisco UCS FEX and FIs form port channels automatically based on the
chassis discovery policy providing a link resiliency to the Cisco UCS C-Series Server. This is identical
to the behavior of the FEX to fabric interconnect connectivity. From a logical perspective the virtual
circuits formed within the Cisco UCS domain are consistent between B and C Series deployment models
and the virtual constructs formed at the VMware vSphere or Cisco Nexus 1000v layer are unaware in
either case.
VMware vSphere 5.1 on FlexPod with Nexus 7000 Using FCoE
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Figure 16, the FlexPod defines two FCoE port channels (Po1 & Po2) and two LAN port
shows the connectivity of the UCS C-Series server into the Cisco UCS domain. From a