VERITAS Volume Manager 3.1 Administrator's Guide

Cluster Functionality
Disks in VxVM Clusters
Chapter 7 307
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:
default_activation_mode= activation-mode
enable_activation=true
where activation-mode is: off , shared-write , shared-read ,
read-only , or exclusive-write .
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 default file is edited when the vxconfigd utility is running, the
vxconfigd utility must be restarted for the changes in the default file to
take effect.
Exclusive write Shared write Read only Shared
read
Exclusive write Fail Fail Fail Succeed
Shared write Fail Succeed Fail Succeed
Read only Fail Fail Succeed Succeed
Shared read Succeed Succeed Succeed Succeed
Table 7-2 Allowed and Conflicting Activation Modes
Notes:
• 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.
• If the default activation node is anything other than off, an
activation following a cluster join, or a disk group creation or import
may fail if another node in the cluster has activated the disk group in
a conflicting mode.