Veritas Volume Manager 5.0 Administrator's Guide (September 2006)

400 Administering cluster functionality
Cluster initialization and configuration
vxconfigd daemon
The VxVM configuration daemon, vxconfigd, maintains the configuration of VxVM
objects. It receives cluster-related instructions from the kernel. A separate copy of
vxconfigd runs on each node, and these copies communicate with each other over a
network. When invoked, a VxVM utility communicates with the vxconfigd daemon
running on the same node; it does not attempt to connect with vxconfigd daemons on
other nodes. During cluster startup, the kernel prompts vxconfigd to begin cluster
operation and indicates whether it is a master node or a slave node.
When a node is initialized for cluster operation, the vxconfigd daemon is notified that
the node is about to join the cluster and is provided with the following information from
the cluster monitor configuration database:
■ cluster ID
■ node IDs
■ master node ID
■ role of the node
■ network address of the vxconfigd daemon on each node (if applicable)
On the master node, the vxconfigd daemon sets up the shared configuration by
importing shared disk groups, and informs the kernel when it is ready for the slave nodes
to join the cluster.
On slave nodes, the vxconfigd daemon is notified when the slave node can join the
cluster. When the slave node joins the cluster, the vxconfigd daemon and the VxVM
kernel communicate with their counterparts on the master node to set up the shared
configuration.
When a node leaves the cluster, the kernel notifies the
vxconfigd daemon on all the other
nodes. The master node then performs any necessary cleanup. If the master node leaves
the cluster, the kernels select a new master node and the
vxconfigd daemons on all nodes
are notified of the choice.
The vxconfigd daemon also participates in volume reconfiguration as described in
“Volume reconfiguration” on page 401.
vxconfigd daemon recovery
In a cluster, the vxconfigd daemons on the slave nodes are always connected to the
vxconfigd daemon on the master node. If the vxconfigd daemon is stopped, volume
reconfiguration cannot take place. Other nodes can join the cluster if the
vxconfigd
daemon is not running on the slave nodes.
If the vxconfigd daemon stops, different actions are taken depending on which node
this occurred: