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

Administering VxVM in Cluster Environments

266 VERITAS Volume Manager Administrator’s Guide

Changing the Activation Mode on a Shared Disk Group

Note The activationmode for accessby a clusternodeto ashareddiskgroupis setonthat

node.

The activation mode of a shared disk group can be changed using the following

command:

# vxdg -g diskgroup set activation=mode

The activation mode is one of exclusive-write or ew, read-only or ro,

shared-read or sr, shared-write or sw, or off. See “Activation Modes of Shared

Disk Groups” on page 249 for more information.

Setting the Connectivity Policy on a Shared Disk Group

Note The connectivity policy for a shared disk group can only be set on the master node.

The vxedit command may be used to set either the global or local connectivity

policy for a shared disk group:

# vxedit -g diskgroup set diskdetpolicy=global|local diskgroup

See “Connectivity Policy of Shared Disk Groups” on page 251 for more information.

Creating Volumes with Exclusive Open Access by a Node

Note Volumes with exclusive open access can only be created on the master node.

Whenusing thevxassist command to createa volume, youcanuse theexclusive=on

attribute to specify that the volume may only be opened by one node in the cluster at a

time. For example, to create the mirrored volume volmir in the disk group dskgrp, and

conﬁgure it for exclusive open, use the following command:

# vxassist -g dskgrp make volmir 5g layout=mirror exclusive=on

Multiple opens by the same node are also supported. Any attempts by other nodes to

open the volume fail until the ﬁnal close of the volume by the node that opened it.

Specifying exclusive=off instead meansthat more than onenode ina cluster can open

a volume simultaneously.