To install plug-ins on the NetVault Backup Server or Client:
1 In the Navigation pane, click Manage Clients.
2 In the NetVault Backup Clients list, select the client, and click Manage.
3 At the lower-right corner of the Installed Plug-ins table, click the Install Plugin button ( + ).
4 Select the platform-specific “.npk” binary file for the plug-in, and click Next to begin installation.
After the plug-in is installed successfully, a message is displayed.
To Install Plugin using command line:
Removing plug-ins:
To remove a plug-in from the NetVault Backup Server or Client
1 In the Navigation pane, click Manage Clients.
2 In the NetVault Backup Clients list, select the client, and click Manage.
3 In the Installed Plug-ins table, select the plug-in, and click the Remove Plugin button ( - ).
4 In the confirmation dialog box, click Remove.
Also For CLI Command to perform Installplugin Refer the CLI Guide
https://support.quest.com/technical-documents/netvault-backup/12.1/cli-reference-guide/24#TOPIC-1007148
installplugin
Description
Installs NetVault Backup plug-ins on the server or client machines. This utility is located in the bin directory.
Syntax
<Netvault Installation path>/util
installplugin <Full path to the .npk installation file> Verify that you provide the full file path to the “.npk” installation file. Enclose the path within quotation marks (“”) if it contains any spaces