2.1.2.1 Configuration and Initialization

Before any nodes can join a new cluster for the first time, the system administrator must supply certain configuration information. This information is supplied during cluster manager setup and is normally stored in some type of cluster manager configuration database. The precise content and format of this information is dependent on the characteristics of the cluster manager.

The type of information required by CVM is as follows:

• Cluster ID

• Node IDs

• Network addresses of nodes

• Port addresses

  When a node joins the cluster, this information is automatically loaded into CVM on that node at node startup time.

  Node initialization is effected through the cluster manager startup procedure, which brings up the various cluster components (such as CVM, the cluster manager, and a distributed lock manager) on the node. Once initialization is complete, applications can be started. The system administrator invokes the cluster manager startup procedure on each node to be joined to the cluster.

  For CVM, initialization consists of loading the cluster configuration information and joining the nodes in the cluster. The first node to join becomes the master node, and later nodes (slaves) join to the master. If two nodes join simultaneously, CVM software chooses the master. Once the join for a given node is complete, that node has access to the shared disks.