The VMware Horizon Client Drive Redirection ADMX template file (vdm_agent_cdr.admx) contains policy settings related to the client drive redirection feature.

Client Drive Redirection settings are in the VMware View Agent Configuration > VMware Horizon Client Drive Redirection folder in the Group Policy Management Editor.

Table 1. Client Drive Redirection Settings
Setting Computer User Properties
Configure drive letter mapping mode X Specifies the drive letter mapping mode. When this setting is enabled, you can select one of the following modes:
  • One to one mapping, which maps the drive letter on the client machine to the same drive letter on the agent machine. For example, drive X on the client machine is mapped to drive X on the agent machine.
  • Defined mapping, which maps drive letters on the client machine to certain drive letters on the agent machine according to a mapping table that is defined in the Define drive letter mapping table group policy setting.

If a drive letter conflict occurs, for example, if a drive letter to be mapped is already in use on the agent machine, the first available drive letter from Z to A is used. If no drive letter is available, a drive letter is not assigned.

This setting is valid only when the Display redirected device with drive letter group policy setting is not disabled.

Define drive letter mapping table X When this setting is enabled, you can click Show and define a drive letter mapping table. In the Value name column, enter the drive letter on the client machine. In the corresponding Value column, enter the drive letter to use on the agent machine.

This setting is valid only when you select Defined mapping in the Configure drive letter mapping mode group policy setting.
Display redirected device with drive letter X Determines whether to display a drive letter for drives that are redirected with the client drive redirection feature.

This setting is enabled by default.

Timeout for drive letter initialization X Specifies how long to wait, in milliseconds, for Windows Explorer to initialize and display a drive letter for drives that are redirected with the client drive redirection feature.

When this setting is disabled or not configured, the default value is 5000 milliseconds.

Policy Settings for Filtering Client Devices

Device filtering settings for Client Drive Redirection are in the VMware View Agent Configuration > VMware Horizon Client Drive Redirection > Device Filtering folder in the Group Policy Management Editor.

The device filtering feature works only for Horizon Client for Windows, Mac, and Linux versions 5.1 and later. When these device filtering policies are set, client drive redirection is disabled for other clients, including Android, iOS, and Chrome, and Horizon Client versions 5.0 and earlier.

Table 2. Device Filtering Settings
Setting Computer User Properties
Exclude Vid/Pid Device X Excludes devices that have a specified vendor and product ID from being redirected with the client drive redirection feature.

You must specify ID numbers in hexadecimal. You can use the wildcard character (*) in place of individual digits in an ID. Use a semicolon to separate multiple devices. For example: 

vid-0781_pid-554c;vid-0781_pid-****

The default value is undefined (no devices are excluded).

This setting takes precedence over the Include Vid/Pid Device setting.

Note: To disable client drive redirection for all devices, you can specify vid-****_pid-****.
Include Vid/Pid Device X Specifies devices that have a specified vendor and product ID that can be redirected with the client drive redirection feature.

You must specify ID numbers in hexadecimal. You can use the wildcard character (*) in place of individual digits in an ID. Use a semicolon to separate multiple devices. For example: 

vid-054C_pid-0099;vid-8888_pid-****

The default value is undefined (all devices are included).