VERITAS Volume Manager 4.1 Administrator's Guide

Administering Cluster Functionality
Cluster Initialization and Configuration
Chapter 10 363
If a vxconfigd daemon on any node goes away during reconfiguration,
all nodes are notified and the operation fails. If any node leaves the
cluster, the operation fails unless the master has already committed it. If
the master node leaves the cluster, the new master node, which was
previously a slave node, completes or fails the operation depending on
whether or not it received notification of successful completion from the
previous master node. This notification is performed in such a way that if
the new master does not receive it, neither does any other slave.
If a node attempts to join a cluster while a volume reconfiguration is
being performed, the result of the reconfiguration depends on how far it
has progressed. If the kernel has not yet been invoked, the volume
reconfiguration is suspended until the node has joined the cluster. If the
kernel has been invoked, the node waits until the reconfiguration is
complete before joining the cluster.
When an error occurs, such as when a check on a slave fails or a node
leaves the cluster, the error is returned to the utility and a message is
sent to the console on the master node to identify on which node the error
occurred.
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