VERITAS Storage Foundation 4.1 Cluster File System HP Serviceguard Storage Management Suite Extracts, December 2005

Overview of Cluster Volume Management
102 Installation and Administration 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.
Caution When enabling activation using the defaults file, it is advisable 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.
Caution If the default activation mode 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.
You can also use the vxdg command to change the activation mode on a shared disk
group.
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