Releasing NVIDIA RTX Virtual Workstation License(s) on the License Server Manager

One of the frequent questions I’ve been asked in the past for VDI deployments that are accelerated with NVIDIA GPU GRID cards is how we can release assigned licenses to VDIs that no longer exist. Scenarios that can cause this is if a set of virtual desktops were deployed but then had to get redeployed the same evening because of a required change in configuration (I had to do this once when I needed to change the GPU memory allocation for the desktops).

Failure to have sufficient licenses for the VDIs will display the following message upon logging into the virtual desktop:

Failed to acquire NVIDIA license.

Failed to acquire NVIDIA RTX Virtual Workstation license. Click here for more information.

The short answer is that there isn’t a way to do this via the on-premise license server, command line or the NVIDIA Application Hub, and the recommended method is to either reduce the lease time for the license or completely remove all the licenses allocated to the desktops.

The steps to modify the lease time are as follows:

1. Log onto the VDI master image
2. Open the registry editor and browse to HKEY_LOCAL_MACHINE\SOFTWARE\NVIDIA Corporation\Global\GridLicensing
3. Edit the LicenseInterval DWord (REG_DWORD) and configure the interval time that represents how long the license lease is valid for

The integer configured should be within the range 10-10080 that specifies the period of time in minutes for which a license can be borrowed after it is checked out. After this period has elapsed, the client must obtain a new license from the server.
The default is 1440 minutes, which corresponds to a period of 1 day. The value can be reduce to an hour so a new license would be reissued.

The environment I was working with already had the lease time configured to be a day (default) and further reducing it was not ideal in case we ever had a license server failure so I opted to use the 2^nd method, which was to completely remove all the licenses allocated to the desktops so new ones would be issued. It is worth noting that I was told by the NVIDIA support engineer that this does not adversely affect the VDIs currently in use so it can be performed during regular hours.

The following are the steps:

1. Begin by logging into the NVIDIA Application Hub via the URL: https://nvid.nvidia.com/dashboard/

2. Select NVIDIA LICENSING PORTAL:

3. Navigate to LICENSE SERVERS, expand the License Server node and click on Download:

4. The license file representing the licenses will be downloaded:

5. On the on-premise NVIDIA licensing server, stop FlexNet License Server - nvidia service:

6. Navigate to the path: C:\Windows\ServiceProfiles\NetworkService\flexnetls\:

7. Rename the nvidia folder to nvidia-old:

8. Start FlexNet License Server - nvidia service:

9. Open the license portal on the on-premise NVIDIA license server, navigate to License Management, ensure that the server is up, and the following error message is NOT present:

Connection error: Please make sure the FNE server is up and running

10. Confirm that the nvidia folder previously renamed has been recreated:

11. Confirm that there are no licensed clients listed:

12. With the server services up, proceed to upload the previously downloaded license file (.bin):

13. Confirm that the message Successfully applied license file to the license server. is displayed:

14. Navigating back to the Licensed Clients window should initially show an empty list and then new clients being listed:

Enable Security Authentication for NVIDIA License Server Manager

Those who have worked with the NVIDIA License Server Manager that is deployed to provide virtual desktops with GPU licenses will quickly notice that the default install does not provide any security for the management console as navigating to the URL: http://localhost:8080/licserver/ will bring you straight into the console without authentication. Given that I’ve been asked many times in the past about securing this portal, this post serves to demonstrate the process.

Enabling the requirement for logging in as shown in the screenshot below cannot be done via the GUI:

To enable the authentication requirement, we’ll need to use the nvidialsadmin.bat via the command line. The nvidialsadmin.bat can be found in the directory C:\NVIDIA\LicenseServer\enterprise on the licensing server:

Enable Security for the NVIDIA License Server Manager

1. Begin by launching a command prompt as an administrator and navigating to the directory: C:\NVIDIA\LicenseServer\enterprise

2. Execute the following command to set the security flag as true:

nvidialsadmin.bat -server http://127.0.0.1:7070 -config -set security.enabled=true

3. Next, execute the following command with the default password for the admin account (Admin@123) and set the new password (Update the New-Password1 value to the password desired):

nvidialsadmin.bat -server http://127.0.0.1:7070 -authorize admin Admin@123 -users -edit admin New-Password1

4. Proceed to restart the Apache Tomcat 9.0 Tomcat9 service in the services console on the license server:

5. Wait for the license server to be fully started then try to navigate to the console at http://localhost:8080/licserver/ to verify that credentials are required:

Disable Security for the NVIDIA License Server Manager

1. To disable the security login requirement execute the following command with the configured password to authorize the session:

nvidialsadmin -server http://127.0.0.1:7070 -authorize admin New-Password1

2. Then set the security flag to false:

nvidialsadmin.bat -server http://127.0.0.1:7070 -authorize admin New-Password -config -set security.enabled=false

3. Proceed to restart the Apache Tomcat 9.0 Tomcat9 service in the services console on the license server:

4. Wait for the license server to be fully started then try to navigate to the console at http://localhost:8080/licserver/ to verify that credentials are no longer required.