VERITAS Volume Manager 3.5 Administrator's Guide (September 2002)

Chapter 10, Administering Cluster Functionality
Cluster Initialization and Configuration
255
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
On the master node, the vxconfigd daemon sets up the shared configuration by
importing shared disk groups, and informs the vxclustd daemon 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 vxclustd daemon notifies the kernel on all the other
nodes. The master node then performs any necessary cleanup. If the master node leaves
the cluster, the kernels choose 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 254.
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 and other nodes cannot join the cluster until it is
restarted. If a cluster monitor is enabled, it may try to fail over VxVM to another node in
the cluster. Itis thereforeinadvisable to stopthe vxconfigd daemon on any cluster node.
Different actions are taken depending on which node the vxconfigd daemon is stopped: