Cisco Nexus 7000 Design Manual page 48

FlexPod Implementation and Design
B) or assign no preference allowing the Cisco UCS Manager to provision active dynamic vNICs equally
between fabric interconnects. The maximum number of Virtual Interfaces (VIF) that can be defined on
a Cisco VIC Adapter depends on the following criteria and must be considered in any VM-FEX design:
The presence of jumbo frames
•
• The combination of Fabric Interconnects (6100 / 6200) and Fabric Extenders (2104 / 2204/ 2208)
• The maximum number of port links available to the Cisco UCS IOM Fabric Extender
• The number of supported static and dynamic vNICs and vHBAs on the Cisco VIC Adapters
The version of vSphere version
•
Cisco VM-FEX requires that the ESXi host must have the Cisco Virtual Ethernet Module (VEM)
Note
software bundled installed.
For more information on the configuration limits associated with VM-FEX, see:
http://www.cisco.com/en/US/partner/docs/unified_computing/ucs/sw/configuration_limits/2.1/b_UCS
_Configuration_Limits_2_1.html
Cisco VM-FEX is configurable in standard or high performance mode from the Cisco UCS Manager port
profile tab. In standard mode, some of the ESXi nodes virtualization stack is used for VM network I/O.
In high performance mode, the VM completely bypasses the hypervisor and DVS accessing the Cisco
VIC adapter directly. The high performance model takes advantage of VMware DirectPath I/O.
DirectPath off loads the host CPU and memory resources that are normally consumed managing VM
networks. This is a design choice primarily driven by performance requirements and VMware feature
availability.
Note The following VMware vSphere features are only available for virtual machines configured with
DirectPath I/O on the Cisco UCS through Cisco Virtual Machine Fabric Extender (VM-FEX) distributed
switches.
vMotion
•
Hot adding and removing of virtual devices
•
Suspend and resume
•
High availability
•
DRS
•
Snapshots
•
The following features are unavailable for virtual machines configured with DirectPath on any server
platform:
Record and replay
•
Fault tolerance
•
For more information on Cisco VM-FEX Best Practices for VMware ESX Environment Deployment
Guide, see:
http://www.cisco.com/en/US/solutions/collateral/ns340/ns517/ns224/ns944/vm_fex_best_practices_de
ployment_guide.html#wp9001031
VMware vSphere 5.1 on FlexPod with Nexus 7000 Using FCoE
48