VERITAS Volume Manager 3.5 Administrator's Guide (September 2004)

Administering Cluster Functionality
Overview of Cluster Volume Management
Chapter 10344
Table 10-2 summarizes the allowed and conflicting activation modes for
shared disk groups:
Shared disk groups can be automatically activated in any mode during
disk group creation or during manual or auto-import. To control
auto-activation of shared disk groups, the defaults file
/etc/default/vxdg must be created.
The defaults file /etc/default/vxdg must contain the following lines:
enable_activation=true
default_activation_mode=activation-mode
The activation-mode is one of exclusive-write, read-only,
shared-read, shared-write, or off.
NOTE When enabling activation using the defaults file, it is recommended that
the defaults file be identical on all nodes in the cluster. Otherwise, the
results of activation are unpredictable.
When a shared disk group is created or imported, it is activated in the
specified mode. When a node joins the cluster, all shared disk groups
accessible from the node are activated in the specified mode.
If the defaults file is edited while the vxconfigd daemon is already
running, the vxconfigd process must be restarted for the changes in the
defaults file to take effect.
Table 10-2 Allowed and Conflicting Activation Modes
Disk group
activated in
cluster as...
Attempt to activate disk group on another node as...
exclusive-
write
read-only shared-read shared-write
exclusive-writ
e
Fails Fails Succeeds Fails
read-only Fails Succeeds Succeeds Fails
shared-read Succeeds Succeeds Succeeds Succeeds
shared-write Fails Fails Succeeds Succeeds