The Cisco Unified Computing System (UCS) has a unique architecture that integrates compute, data network access, and storage network access into a common set of components under a single management portal (single-pane-of-glass portal). The Cisco UCS combines access layer networking and servers. This high-performance, next-generation server system provides a data center with a high degree of workload agility and scalability. The hardware and software components support Cisco’s unified fabric, which runs multiple types of data center traffic over a single converged network adapter. Figure 12-1 shows UCS management and network connectivity.
Figure 12-1 Cisco Unified Computing System Architecture
The simplified architecture of the Cisco UCS reduces the number of required devices and centralizes switching resources. By eliminating switching inside a chassis, Cisco significantly reduced the network access layer fragmentation. The Cisco UCS implements a Cisco unified fabric within racks and groups of racks, supporting Ethernet and Fibre Channel protocols. This simplification reduces the number of switches, cables, adapters, and management points by up to two-thirds. All devices in a Cisco UCS domain remain under a single management domain, which remains highly available through the use of redundant components. The Cisco UCS architecture provides the following features (see Figure 12-2):
High availability: The management and data plane of the Cisco UCS is designed for high availability and redundant access layer fabric interconnects. In addition, the Cisco UCS supports existing high-availability and disaster recovery solutions for the data center, such as data replication and application-level clustering technologies.
Scalability: A single Cisco UCS domain supports multiple chassis and their servers, all of which are administered through one Cisco UCS Manager.
Flexibility: A Cisco UCS domain allows you to quickly align computing resources in the data center with rapidly changing business requirements. This built-in flexibility is determined by whether you choose to fully implement the stateless computing feature. Pools of servers and other system resources can be applied as necessary to respond to workload fluctuations, support new applications, scale existing software and business services, and accommodate both scheduled and unscheduled downtime. Server identity can be abstracted into a mobile service profile that can be moved from server to server with minimal downtime and no need for additional network configuration. With this level of flexibility, you can quickly and easily scale server capacity without having to change the server identity or reconfigure the server, LAN, or SAN. During a maintenance window, you can quickly do the following:
Deploy new servers to meet unexpected workload demand and rebalance resources and traffic.
Shut down an application, such as a database management system, on one server and then boot it up again on another server with increased I/O capacity and memory resources.