VERITAS Volume Manager 4.1 Administrator's Guide

Administering Cluster Functionality
Cluster Initialization and Configuration
Chapter 10 365
on the slave node has successfully reconnected to the vxconfigd
daemon on the master node, it has very little information about the
shared configuration and any attempts to display or modify the
shared configuration can fail. For example, shared disk groups listed
using the vxdg list command are marked as disabled; when the
rejoin completes successfully, they are marked as enabled.
• If the vxconfigd daemon is stopped on both the master and slave
nodes, the slave nodes do not display accurate configuration
information until vxconfigd is restarted on the master and slave
nodes, and the daemons have reconnected.
If the vxclustd daemon determines that the vxconfigd daemon is not
running on a node during a cluster reconfiguration, vxclustd restarts
vxconfigd automatically.
NOTE The -r reset option to vxconfigd restarts the vxconfigd daemon and
recreates all states from scratch. This option cannot be used to restart
vxconfigd while a node is joined to a cluster because it causes cluster
information to be discarded.
Node Shutdown
Although it is possible to shut down the cluster on a node by invoking the
shutdown procedure of the node’s cluster monitor, this procedure is
intended for terminating cluster components after stopping any
applications on the node that have access to shared storage. VxVM
supports clean node shutdown, which allows a node to leave the
cluster gracefully when all access to shared volumes has ceased. The host
is still operational, but cluster applications cannot be run on it.
The cluster functionality of VxVM maintains global state information for
each volume. This enables VxVM to determine which volumes need to be
recovered when a node crashes. When a node leaves the cluster due to a
crash or by some other means that is not clean, VxVM determines which
volumes may have writes that have not completed and the master node
resynchronizes these volumes. It can use dirty region logging (DRL) or
FastResync if these are active for any of the volumes.
Clean node shutdown must be used after, or in conjunction with, a
procedure to halt all cluster applications. Depending on the
characteristics of the clustered application and its shutdown procedure, a