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

Overview of Cluster Volume Management
250 VERITAS Volume Manager Administrator’s Guide
The table “Allowed and Conflicting Activation Modes” 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.
Note If the default activation node is anything other than off, an activation following a
cluster join, or a disk group creation or import can fail if another node in the cluster
has activated the disk group in a conflicting mode.
To display the activation mode for a shared disk group, use the vxdg list diskgroup
command as described in “Listing Shared Disk Groups” on page 262.
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-write Fails Fails Succeeds Fails
read-only Fails Succeeds Succeeds Fails
shared-read Succeeds Succeeds Succeeds Succeeds
shared-write Fails Fails Succeeds Succeeds