Administration

Table Of Contents
When you first install Horizon 7 on a system, the message security mode is set to Enhanced. If you
upgrade Horizon 7 from a previous release, the message security mode remains unchanged from
its existing setting.
Important If you plan to change an upgraded Horizon 7 environment from Enabled to Enhanced,
you must first upgrade all Connection Server instances, security servers, and Horizon 7 desktops
to Horizon 6 version 6.1 or a later release. After you change the setting to Enhanced, the new
setting takes place in stages.
1 You must manually restart the VMware Horizon View Message Bus Component service on all
Connection Server hosts in the pod, or restart the Connection Server instances.
2 After the services are restarted, the Connection Server instances reconfigure the message
security mode on all desktops and security servers, changing the mode to Enhanced.
3 To monitor the progress in Horizon Administrator, go to View Configuration > Global
Settings.
On the Security tab, the Enhanced Security Status item will show Enhanced when all
components have made the transition to Enhanced mode.
Alternatively, you can use the vdmutil command-line utility to monitor progress. See Using
the vdmutil Utility to Configure the JMS Message Security Mode.
Horizon 7 components that predate Horizon 6 version 6.1 cannot communicate with a Connection
Server 6.1 instance that uses Enhanced mode.
If you plan to change an active Horizon 7 environment from Disabled to Enabled, or from Enabled
to Disabled, change to Mixed mode for a short time before you make the final change. For
example, if your current mode is Disabled, change to Mixed mode for one day, then change to
Enabled. In Mixed mode, signatures are attached to messages but not verified, which allows the
change of message mode to propagate through the environment.
Using the vdmutil Utility to Configure the JMS Message Security Mode
You can use the vdmutil command-line interface to configure and manage the security
mechanism used when JMS messages are passed between Horizon 7 components.
Syntax and Location of the Utility
The vdmutil command can perform the same operations as the lmvutil command that was
included with earlier versions of Horizon 7. In addition, the vdmutil command has options for
determining the message security mode being used and monitoring the progress of changing all
Horizon 7 components to Enhanced mode. Use the following form of the vdmutil command from
a Windows command prompt.
vdmutil command_option [additional_option argument] ...
Horizon 7 Administration
VMware, Inc. 39