2.3 What is Oracle VM Manager?

Management for the Oracle VM environment is provided by Oracle VM Manager, a transaction-based framework that also includes an integrated database, a web-based management user interface and a command line interface. Since Oracle VM can continue to function normally even during periods of downtime for the Oracle VM Manager, high-availability and redundancy are not generally required for Oracle VM Manager.

Since Oracle VM Manager is a multi-user application with a variety of different interfaces that allow components to be configured and managed, it is possible that two users may attempt to perform a configuration change on the same element at the same time. In this situation, Oracle VM Manager processes the first configuration change that reaches its queue, and temporarily locks the element for any other changes. The second configuration change fails because the information that it has is stale. Usually an error is returned for the configuration change that fails. This error notifies the user that the object was locked while fetching. To work around this problem, the user that receives the error must refresh the view of the object that was being updated and resubmit the changes.

When describing the architecture of Oracle VM Manager, it is best to understand that it is composed of various inter-related components. The fundamental components consist of the Oracle VM Manager Server and the Oracle VM Manager Database. All other Oracle VM Manager components interface with the Oracle VM Manager Server via an API.