HP UX Serviceguard Storage Management Software Either of the write modes on other nodes will fail

Cluster Volume Manager Administration

Overview of Cluster Volume Management

The activation mode of a disk group controls volume I/O from different nodes in the cluster. It is not possible to activate a disk group on a cluster node, if it is activated in a conflicting mode on another node in the cluster.

Table 4-1	Activation Modes for Shared Disk Groups
	Activation Mode	Description
	exclusive-write	The node has exclusive write access to the disk group. No other
	(ew)	node can activate the disk group for write access.
	read-only (ro)	The node has read access to the disk group and denies write
		access for all other nodes in the cluster. The node has no write
		access to the disk group. Attempts to activate a disk group for
		either of the write modes on other nodes will fail.
	shared-read (sr)	The node has read access to the disk group. The node has no
		write access to the disk group, however other nodes can obtain
		write access.
	shared-write (sw)	The node has write access to the disk group.
	off	The node has neither read or write access to the disk group.
		Query operations on the disk group are permitted.

The following table summarizes allowed and conflicting activation modes or shared disk groups:

Table 4-2	Allowed and Conflicting Activation Modes
	Disk group	Attempt to activate disk group on another node as...
	activated in	exclusive-	read-only	shared-read	shared-write
	cluster as...
		write
	exclusive-wr	Fails	Fails	Succeeds	Fails
	ite
	read-only	Fails	Succeeds	Succeeds	Fails
	shared-read	Succeeds	Succeeds	Succeeds	Succeeds
	shared-write	Fails	Fails	Succeeds	Succeeds

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

Where activation-modeis one of the following:

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