With traditional servers, I/O is inflexible and rigid. Changing the I/O configuration generally requires physical intervention and results in application downtime. The rapid adoption of virtualization brings with it additional I/O configuration complexity. Network interface virtualization (NIV) helps address these issues by creating greater numbers of I/O connections to a given server while limiting the number of required physical connections to the server.
Cisco developed the Cisco® UCS M81KR Virtual Interface Card to perform network interface virtualization within the Cisco Unified Computing System™. This document discusses how to use the Cisco UCS M81KR's capability to virtualize I/O, combined with other Cisco Unified Computing System features such as a "wire-once" cabling model and service profiles, to make moving or rehosting a physical or virtualized environment a straightforward and easily scaled operation.
Challenge
Data center infrastructure is under increasing pressure due to two related trends: the increasing overall number of transactions and accelerating adoption of virtualization. These trends create unprecedented demand for increasing and managing I/O to every server, both physical and virtual. This demand, in turn, affects overall data center economics and operations in three fundamental ways:
• Need to scale applications while containing physical costs: Most existing data centers deploy servers with multiple network interface cards (NICs) and host bus adapters (HBAs) that all need to be powered, cooled, and stocked for sparing. Adding new servers to keep up with transaction demands also leads to cable and switch proliferation. Looking forward, I/O needs to scale with increasing performance of processor and memory technologies. In a virtual environment, I/O also needs to scale to accommodate virtual machine mobility.
• Need to simplify dynamic operations: Business users expect their applications to be available on demand, which forces IT to repurpose and reprovision servers ever more frequently. Proliferating components and devices - from servers and adapters to switches and cables - creates more management complexity and also more points of potential failure. Since management paradigms are typically device-based and have generally not kept pace with the scale and complexity of physical implementations, troubleshooting becomes ever more challenging. IT organizations often separate server, SAN, and LAN teams, making synchronization of servers with I/O difficult.
• Need to optimize I/O for virtualized environments: Currently it is difficult to apply consistent network policies (security, quality of service [QoS], etc.) as virtual servers move around, or to provide consistent management and troubleshooting mechanisms between a physical and a virtual server.
Cisco Solution
Cisco addresses the I/O challenges faced by customers today with the Cisco UCS M81KR Virtual Interface Card (Figure 1).
Figure 1. Cisco UCS M81KR Virtual Interface Card
The Cisco UCS M81KR is a virtualization-optimized Ethernet and Fibre Channel over Ethernet (FCoE) mezzanine card designed for use with Cisco UCS B-Series Blade Servers. The virtual interface card is a dual-port 10 Gigabit Ethernet adapter that supports up to 128 Peripheral Component Interconnect Express (PCIe) standards-compliant virtual interfaces that can be dynamically configured so that both their interface type (NIC or HBA) and identity (MAC address and worldwide name [WWN]) are established using just-in-time provisioning. These virtual interfaces are administratively defined, and are instantiated on the server at time of service profile assignment. These virtual interfaces are seen by the BIOS, OS, and hypervisors as regular PCIe devices.
The architecture of the Cisco UCS M81KR allows for the presentation of the virtualized adapter both inward toward the CPU and outward toward the network from the perspective of the physical connection to the fabric. Because the existence, identity, and policy are applied from the service profile to the adapter, these devices are known to the BIOS prior to the operating system boot. Normal scans of the PCI bus by the system are not only unaffected, but the information is persistent across multiple system boots and migrations of the service profile to other blades within the Cisco Unified Computing System. This behavior is consistent with the stateless model that is a fundamental part of the Cisco Unified Computing System.
The administrative team can define policies to the individual virtual interfaces directly, with no restrictions on subgroupings of these interfaces. Cisco VN-Link technology allows the unique identification of the virtual adapters and presents them as logical interfaces (which are logically tied directly to the virtual adapters) on the Cisco UCS 6100 Series Fabric Interconnects. Cisco VN-Link technology also allows administrators to configure policy groups and to include the logical interfaces in this grouping.
Within virtualized environments, the Cisco UCS M81KR offers close integration with VMware vCenter. As these adapters are added, moved, or deleted from a VMware ESX server, the network policy and management information (for example, counters) can be controlled through VMware vCenter.
Solution Benefits
The Cisco UCS M81KR offers a number of benefits to address the challenges of today's data center.
Scale Applications and Contain Costs
The Cisco UCS M81KR offers a high-performance unified I/O architecture that enables a "wire-once" deployment model. It dramatically reduces the number of adapters and switches that must be purchased, cabled, configured, powered, cooled, and secured. Instead of using multiple different types of adapters, switches, and management tools, customers can use a single 10-Gbps converged network adapter (CNA) and unified fabric to simplify the infrastructure. Less physical infrastructure makes the Cisco Unified Computing System highly energy-efficient. Unified I/O architecture along with the innovative fabric extender I/O model also helps significantly reduce cabling.
The Cisco UCS M81KR is a high-performance, dual-port 10-Gbps adapter that delivers more than 600,000 I/O operations per second (IOPS) with very low latency, helping eliminate any I/O bottlenecks for I/O-intensive applications. Further, the Cisco adapter allows great flexibility in the number of virtual interfaces that a user can create to meet the growing I/O connectivity needs of different applications. To scale I/O, IT administrators need a way to create multiple distinct I/O interfaces to a given server while containing the number of physical connections. Further, each I/O interface needs QoS capabilities to prioritize the different types of I/O traffic. The Cisco UCS M81KR adapter helps achieve that goal by applying QoS policies through the Network Interface Virtualization interfaces. This capability particularly helps scale I/O for a virtualized server where VM mobility is important.
Simplify Dynamic Operations
IT infrastructure needs to adapt to changing business needs. The Cisco Unified Computing System abstracts the characteristics of the physical infrastructure and manages them through service profiles in Cisco UCS Manager. For example, an IT manager in a financial institution may use data center servers as virtual desktop interface (VDI) servers during the day, and at night repurpose them to run analytics useful for the next day. In this example, VDI servers may need two HBAs and six NICs, analytic servers may need only two NICs. The Cisco UCS M81KR is the only adapter on the market that can create different combinations of NICs and HBAs dynamically to enable a truly stateless computing infrastructure. The IT manager can very easily provision and configure these adapters using a service profile in Cisco UCS Manager.
Resilience is very important in an agile and flexible data center. Most customers use some form of NIC teaming software that needs to be provided by the NIC vendor for every OS and hypervisor. NIC teaming also requires certification for every application environment. The Cisco UCS M81KR offers fabric failover, which enables interface failover at a physical level without involvement of the OS or hypervisor or certification overhead.
Cisco UCS Manager also simplifies and facilitates collaboration between the server and network groups. The network administrator can define network profiles that can be used by the server administrator to define the service profile. In a virtualized environment, the Cisco UCS M81KR integrates very tightly with VMware vCenter, VMware's management tool. A profile for a virtual NIC (vNIC) can be defined in Cisco UCS Manager and applied by the server administrator to a virtual machine through VMware vCenter in a transparent and collaborative way.
Optimize I/O for Virtualized Environments
A typical virtualized server often connects to multiple distinct LAN and SAN interfaces to provide separate connectivity for VMkernel, service console, and virtual machine production traffic and shared SAN storage. In such a deployment, the use of four to eight NICs and two or more HBAs is common. The Cisco UCS M81KR is the only adapter on the market today that allows a user to create these from a single dual-port 10-Gbps adapter and apply network policies to each. Hence, it helps customers consolidate multiple NICs and HBAs (and the associated Ethernet and storage ports) and save costs.
Since a consistent operational model between physical and virtual servers is necessary to facilitate virtualization automation, the Cisco UCS M81KR uses the VN-Link capabilities jointly developed by Cisco and VMware to manage and operate interfaces on a virtual server in a way that closely follows the operational model for interfaces on a physical server. It enables the network to be virtual machine aware. Further, management of the Cisco UCS M81KR is tightly integrated with VMware vCenter. Network policies and configurations can be created in Cisco UCS Manager by a network administrator, exported to VMware vCenter, and applied to a virtual machine by a server administrator using VMware vCenter. This capability helps customers greatly simplify management of adapters and policies.
The Cisco UCS M81KR can create up to 128 virtual adapters and map them to different virtual machines in a VMware deployment without limiting any virtualization capabilities such as VMware VMotion. As a first step, each virtual machine connects to a Cisco distributed virtual switch (DVS) and then connects to the virtual adapter through pass-through switching. Pass-through switching helps free up CPU cycles that are normally used to provide networking functions, resulting in better virtual server performance.
The adapter has built-in architectural support for each virtual machine to directly access the adapter hardware, bypassing the hypervisor completely. This capability relieves some of the computing burden on the hypervisor and further improves performance, without sacrificing crucial benefits such as VMware VMotion.
Use Cases
The Cisco UCS M81KR can provide significant benefits for all application environments. Several scenarios are addressed particularly well by the capabilities offered by the Cisco UCS M81KR:
• VMware virtualization: The Cisco UCS M81KR helps reduce the number of physical adapters, simplify management, increase hypervisor performance, and facilitate collaboration between different groups.
• Database deployments: The Cisco UCS M81KR helps reduce the number of physical adapters, simplify management, and scale performance for demanding applications such as databases.
• Infrastructure as a service (IaaS): The Cisco UCS M81KR helps reduce the number of physical adapters, repurpose servers dynamically, and reliably scale performance for the different services.
Conclusion
The Cisco UCS M81KR Virtual Interface Card provides many new capabilities through its innovative technology. With it, the user can:
• Reduce physical infrastructure by consolidating and virtualizing multiple NICs and HBAs
• Simplify operations
• Facilitate collaboration between different IT groups
• Enable a stateless and agile infrastructure
• Provide a scalable and high-performance I/O architecture
