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

About CVM
68 Installation and Administration Guide
The following table 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
To place activation modes under user control, create a defaults file /etc/default/vxdg
containing the following lines:
enable_activation=true
default_activation_mode=activation-mode
The variable activation-mode represents exclusive-write, read-only, shared-read,
shared-write, or off. Note that when enabling activation using the defaults file, VERITAS
recommends the file be identical on each node in the cluster. Otherwise, activation results
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 changes to take effect.
Caution If the default activation node is anything other than off, an activation following
a cluster join, or disk group creation or import, can fail if another node in the
cluster has activated the disk group in a conflicting mode.
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