Bare Metal Servers (BMSs) provide both the stability of traditional physical servers and the high scalability of cloud resources. BMSs meet your requirements for high-performance computing and help you build hybrid clouds. BMSs have all the features and advantages of physical servers and support secondary virtualization. The BMS service allows you to provision BMSs using the XenServer OS. You can build a XenServer private cloud based on the BMS cluster and seamlessly migrate your core applications to the cloud. Service VMs in the XenServer private cloud can communicate with Elastic Cloud Servers (ECSs) to provide you with a more flexible solution to migrate services to the cloud.
This document provides a reference solution for deploying a XenServer system using BMSs. You can also deploy the XenServer system in a different mode based on the capabilities provided by the public cloud.
You need to use computing resources of various types and forms in the cloud. Only a combination of physical servers and VMs, instead of VMs alone, can meet requirements in complex application scenarios. Some special application scenarios have high requirements on host performance and stability, or have strict requirements on data security and supervision. VMs cannot meet customer requirements and exclusively used physical servers are required. XenServer on BMS provides you with a more reliable, comprehensive, and flexible way to migrate your services to the cloud.
Some enterprises have successful experience in virtualization services deployed in private cloud data centers and have many talents in virtualization. When migrating services to the public cloud, these enterprises attach great importance to security and transformation of their talent skills. XenServer on BMS does not require service reconstruction, talent skill transformation, or any change to existing O&M tools and experience.
In XenServer on BMS, at least two BMSs are required. One is a multi-NIC Windows BMS with XenCenter installed that functions as the management node of the virtualization cluster. The other is a multi-NIC XenServer BMS that is used to provision service VMs. BMSs of this type can be added based on service requirements (single node and cluster).
If service VMs need to provide services to the Internet, an EIP must be bound to the BMS used to provision service VMs. If a cluster contains multiple BMSs, you can create a NAT gateway and add a DNAT rule to it enable multiple BMSs to share an EIP. This reduces management cost.
If service VMs only communicate with ECSs in the same VPC, you do not need to assign an EIP.
The user-defined network in Figure 1 is a network type designed for the XenServer on BMS solution. This network provides functions similar to those of the VPC.