Brain of the Virtualized Data Center
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Contents
1 Challenges of Server Virtualization
... 3
1.1 The virtual network breaks traditional network boundaries ... 3
1.2 The live migration function of VMs requires simultaneous migration of network configurations ... 4
1.3 Network resources are allocated according to service needs ... 4
2 Features and Advantages
... 5
2.1 Automatic discovery of E2E network topologies ... 5
2.2 Centralized management and intelligent distribution ... 5
2.3 Proactive configuration learning ... 6
2.4 P+V unified network management ... 6
2.5 On-demand allocation of network resources ... 6
2.6 Compatibility with mainstream virtualization software ... 6
2013-03-18 Huawei confidential. No spreading without permission. Page 3 of 7 As one of the core technologies for cloud computing, server virtualization can significantly reduce IT costs, improve service deployment flexibility, and reduce operation and maintenance (O&M) costs. It has won recognition from a large number of customers and is widely used.
However, server virtualization brings great challenges to network deployment and data center (DC) management. A physical server is virtualized into multiple logical servers. These logical servers exchange data through a virtual switch, complicating the network architecture. The live migration technology of virtual machines (VMs) allows access users to connect networks from anywhere at any time and allows network administrators to dynamically adjust network configurations. To support the live migration function of VMs, network configurations such as VLAN, ACL, and QoS must be migrated with VMs.
1 Challenges of Server Virtualization
1.1 The virtual network breaks traditional network boundaries
High bandwidth is necessary to satisfy the surge in demand and enhance
Using the server virtualization technology, server virtualization software virtualizes one physical server into multiple virtual servers, and virtual switches allow these virtual servers to connect to each other or to other virtual servers. These virtual switches complicate network management. Virtual switches and physical switches use different
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1.2 The live migration function of VMs requires simultaneous migration of network
configurations
Data disaster recovery is implemented by either hardware or software.
Live migration is the core of virtualization technologies. It can migrate an in-service VM from one physical server to another, as shown in the preceding figure. During the migration, the VM runs normal, without causing service or network interruption. Live migration facilitates O&M and dynamic resource optimization. At the same time, it poses great challenges to the network:
(1) The network connectivity is kept and device configurations must be consistent before and after the migration. (2) The migration destination is unknown and network configurations must also be migrated with the VM
undergoing live migration.
1.3 Network resources are allocated according to service needs
Cloud computing features in "on-demand allocation" and "bandwidth consumption-based charging." This requires that the network is capable of allocating resources based on service needs. If the network can allocate resources based on service needs, not only can resource utilization be improved but system performance can be enhanced (for example, narrowing the broadcast domain of the Layer-2 network and shortening the forwarding table searching time). The current static network resource allocation needs manual intervention and lacks of interaction with upper-layer services. It cannot support on-demand allocation which is required by cloud computing.
2013-03-18 Huawei confidential. No spreading without permission. Page 5 of 7 As a centralized management tool provided by the server virtualization software vendor, the vCenter manages VMs (including creating, deleting, powering on, powering off, and migrating VMs) and other virtual devices such as virtual switches.
As the "brain" of the network, the nCenter automatically collects end-to-end (physical + virtual) network information and dynamically allocates predefined network resources for connected VMs. In this manner, network administrators can focus on VM service configurations. Configuring services on network devices will be automatically completed by the nCenter. This not only enhances the efficiency of service deployment but also reduces device management complexity and configuration errors.
2 Features and Advantages
As the "brain" of the network, the nCenter is intelligent in the following aspects:
2.1 Automatic discovery of E2E network topologies
A Legacy network management system cannot provide a unified E2E view for the entire network since the physical network is isolated from the virtual network. However, using Huawei proprietary technologies, the nCenter
automatically, rapidly, and accurately collects topology information of the physical network and virtual network (virtual switches). Connections between network nodes are visible to network administrators, and O&M efficiency is improved.
2.2 Centralized management and intelligent distribution
Brain of the Virtualized Data Center
2013-03-18 Huawei confidential. No spreading without permission. Page 6 of 7 network devices. When a VM starts operating, the nCenter automatically configures QoS, security policies, and the VLAN between the virtual switches and the gateway. When the VM stops operating, the nCenter automatically deletes these network configurations. When the VM is migrated, the nCenter configures network policies for the VM at the migration destination before the migration is completed, and deletes the configured network policies from the migration source after the migration is completed. This ensures the seamless migration of network policies with the VM.
The service-oriented automatic deployment simplifies network deployment, frees administrators from complicated device configuration commands and processes. In addition, configurations mode is changed from static to dynamic, which realizes resource allocation according to need and policy migration with the VMs.
2.3 Proactive configuration learning
When running, a network automatically generates some dynamic network configurations such as DHCP snooping and IGMP snooping based on VMs' network behaviors. These dynamic network configurations are not maintained by network administrators and dynamically triggered (for example, dynamic policies are triggered by gratuitous ARP packets), which pose great challenges for migration of network configurations with the VMs.
Breaking the restriction on network administration, the nCenter proactively learns dynamic network configurations of VMs and implements centralized management and intelligent distribution.
2.4 P+V unified network management
The virtual network complicates network management. Therefore, unified maintenance and management of the entire network (physical network (P) + virtual network (V)) becomes more complicated. The nCenter has solved this problem. The virtual switches and physical network are both managed by the nCenter. This ensures the consistency of E2E network configurations as well as the visibility and integrity of the network O&M.
2.5 On-demand allocation of network resources
Under the traditional network configuration model, network resources such as VLAN, ACL, and security control settings, are reserved for a server even when the server is powered off. After server virtualization, a large number of VMs may still be in the off state. If network resources are reserved for these VMs, there will be a waste of network resources and it will cause performance degradation. The nCenter provides on-demand allocation of resources to solve this problem. When VMs are shut down, network resources are released. When VMs are powered on, network resources are reallocated.
This mode of network resource allocation as required conforms to the "on-demand" nature of cloud computing.
2.6 Compatibility with mainstream virtualization software
Being aware of virtualization, the nCenter can run on virtualization software from different vendors.
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2.7 Compatibility with the standard virtualization-aware process
With good scalability, the nCenter can work with the Virtual Station Interface (VSI) Discovery and Configuration Protocol (VDP) in compliance with IEEE 802.1Qbg to detect virtualization and implement automatic deployment. As the "brain" of a DC network, the nCenter proactively detects access of VMs and automatically maps service configurations into network configurations. By regarding the network as a whole, it shields administrators from network complexity and simplifies network management.
