Understanding RDS CAL Storage Locations
If you're managing a Remote Desktop Services (RDS) environment, you've likely encountered the concept of RDS Client Access Licenses, or CALs. These licenses are crucial for ensuring legal compliance and proper operation of your RDS infrastructure. A common question that arises is: Where are RDS CALs stored? The answer isn't a single, simple location, but rather a system that involves a license server and its internal database.
The Role of the RDS License Server
At its core, RDS CALs are stored and managed by a dedicated component of the RDS infrastructure: the RDS License Server. This server is responsible for issuing, tracking, and revoking CALs to users and devices accessing your Remote Desktop Session Hosts. Without a properly configured and accessible license server, your RDS deployment will eventually stop allowing new connections.
Key Storage Mechanism: The License Server Database
The primary storage location for RDS CALs is within the internal database of the RDS License Server itself. This database holds information about:
- The types of CALs you possess (per user or per device).
- The number of CALs you have available.
- The specific licenses that have been issued.
When a client device or user connects to an RDS Session Host, the Session Host contacts the license server to request a CAL. The license server then checks its database to see if an available CAL can be issued. If one is available, the license server records the issuance and returns a license to the Session Host, which in turn provides it to the client.
Understanding the "Storage" Process
It's important to clarify that RDS CALs aren't stored as individual files on a standard file system that you can easily browse and open. Instead, think of it as a digital ledger within the license server software. This ledger is designed for the specific purpose of license management.
Installation and Configuration
When you install the RDS Licensing role on a server, you'll need to configure it to point to your license server. This typically involves:
- Installing the RDS Licensing role: This is done through Server Manager on a Windows Server.
- Activating the license server: This process involves communicating with Microsoft's licensing servers to activate your license server and allow it to issue CALs.
- Installing license key packs: After activation, you'll install the CALs you've purchased by entering the product key provided by Microsoft or your reseller.
Once these steps are completed, the license server is ready to manage your RDS CALs.
Where the License Server Itself Resides
The RDS License Server can be installed on a standalone server or on a server that is also running other RDS roles, such as the Remote Desktop Connection Broker or the Remote Desktop Session Host. In smaller environments, it's common for the license server to be co-located with other RDS roles. However, in larger or more robust deployments, it's often recommended to have a dedicated server for the RDS License Server to ensure performance and availability.
Crucially, the licensing information is not stored on the individual Remote Desktop Session Host servers. While Session Hosts request CALs from the license server, they do not store the CALs themselves. This centralization is key to effective license management.
Impact of License Server Failure
If your RDS License Server becomes unavailable, users will likely experience issues connecting to your RDS environment. After a grace period, new connections will be denied because there will be no license server to issue the required CALs. This highlights the importance of ensuring the availability and proper functioning of your RDS License Server.
Troubleshooting and Verification
To verify the status of your RDS CALs and the license server, you'll use the Remote Desktop Licensing Manager tool. This console, accessed via Server Manager, allows you to:
- View the license server and its activation status.
- See the installed license key packs and the number of CALs available.
- Monitor CAL usage.
This tool is your primary interface for understanding how your RDS CALs are being managed and where they are effectively "stored" – within the managed database of the license server.
Frequently Asked Questions (FAQ)
How do I find the RDS License Server in my environment?
You can typically identify your RDS License Server through the Remote Desktop Services Manager or the Server Manager on your Windows Servers. In the Remote Desktop Services Manager, you can see which server is designated as the license server for your deployment.
Why are RDS CALs not stored as individual files?
RDS CALs are not stored as individual files to ensure centralized management, security, and efficient tracking. A database system on the license server provides a robust mechanism for issuing, revoking, and auditing CALs, preventing issues like license duplication or unauthorized use.
What happens if the RDS License Server is unavailable for an extended period?
If the RDS License Server is unavailable, your Remote Desktop Services deployment will eventually stop issuing new CALs. This will prevent new users or devices from connecting to your RDS Session Hosts after a grace period. It's vital to maintain the availability of your license server.
Can I store RDS CALs on multiple servers?
While you can have multiple RDS License Servers for redundancy and scalability, each license server manages its own independent database of CALs. You cannot "split" a single CAL across multiple servers. Each license server must be activated and have license key packs installed separately.
