Chapter 6 Understanding Server Pools and Oracle VM Servers

Oracle VM Servers are very much the work-horses in a Oracle VM environment. It is important to understand their purpose within a deployment, how they are added to a running environment and how they are maintained. A brief overview of Oracle VM Server, its components and its general relationship to other Oracle VM entities is provided in Section 2.2, “What is Oracle VM Server?”.

Some discussion about how servers are added to a deployment is provided in Section 6.1, “How are Oracle VM Servers Added?”. Details on server maintenance are provided in Section 6.3, “How is Maintenance Performed on an Oracle VM Server?”.

Oracle VM Servers are grouped together to form server pools. These server pools are a domain of physical and virtual resources to host virtual machines, perform virtual machine migration, high availability (HA), and so on. Server pools are discussed in Section 6.6, “What are Server Pools used for in Oracle VM?”.

Server pools can take advantage of Oracle VM's clustering facility to achieve HA. Implementation of a clustered server pool is very easy using Oracle VM Manager, but it is important to gain a deeper understanding of the technologies involved and how clustering is facilitated. A very thorough description of clustered server pools is provided in Section 6.8, “How do Server Pool Clusters Work?”

While the most common deployment strategy tends to take advantage of Oracle VM's clustering facility, it is possible to configure a server pool to run in an unclustered arrangement. This approach is discussed in Figure 6.2, “Unclustered Server Pools Using Only NFS Storage”.

While clustering helps to provide HA for the servers within a server pool, Oracle VM allows you to configure whether or not HA should be applied to individual virtual machines. We take a closer look at HA in Section 6.10, “How does High Availability (HA) Work?”

Oracle VM provides additional features specific to how servers and server pools are configured. These include the ability to optimize resource usage or power consumption (see Section 6.11, “What are Server Pool Policies?”); the ability to define which individual servers virtual machines should be allowed to run on (see Section 6.12, “What are Anti-Affinity Groups?”); and the ability to create groups of servers that have compatible processor types to facilitate live migration of virtual machines (see Section 6.13, “What are Server Processor Compatibility Groups?”).