In this recipe, we will quickly go through the architecture of the Virtual Storage Manager, which consists of the following components:
VSM is a web-based application that is typically hosted on a controller machine, which is referred to as a VSM Controller node. You can use a dedicated physical or virtual server that can act as a VSM controller node. The VSM controller software is the core component of VSM that connects to the Ceph cluster through VSM agents. The VSM controller gathers all the data coming from VSM agents and monitors the Ceph cluster. For operations such as cluster creation, pool creation, and so on, the VSM controller sends instructions to VSM Agents to perform the required operation. As shown in the following diagram, Ceph administrators/operators connect to the VSM controller node via HTTPs or APIs, and they can use VSM software. The VSM controller node also connects to the OpenStack controller to configure OpenStack to use Ceph. In addition to the web user interface service, the VSM controller also hosts MariaDB and RabbitMQ.
The VSM agent is a process that runs on all Ceph cluster nodes. The job of the VSM Agent is to send server configuration, cluster health/status information, as well as performance data to the VSM Controller. The VSM agent uses the server manifest file to identify the VSM controller node, authenticate against it, and determine server configuration.
The following diagram illustrates the interaction of different VSM components with each other as well as with OpenStack infrastructure and VSM operators:
