Overview of Microsoft Server Licensing Models
- Core-Based Licensing: Licenses per core in a server, typically with a 16-core minimum.
- Server + CAL (Client Access License): Requires server licenses plus user/device CALs.
- Subscription-Based: Monthly or annual licensing, often used for cloud services like Azure or Microsoft 365.
What are Microsoft Server Licensing Models?
When managing server infrastructure, it is crucial to understand Microsoft Server Licensing Models. Licensing provides the permissions required for users and devices to access software legally.
Navigating the various available options can be challenging, especially for businesses that must remain compliant while controlling costs.
This article will explain the core elements of Microsoft server licensing, including different models, examples, and strategies for optimizing your environment.
Core-Based Licensing
Core-based licensing is a popular approach for Microsoft server products, especially for environments with powerful hardware or many virtual machines.
Key Aspects of Core-Based Licensing:
- Physical Cores Count: Microsoft licenses many of its server products, such as Windows Server, based on the number of physical cores in a server. Each physical core must be licensed.
- Minimum Requirement: Typically, Microsoft requires you to purchase licenses for a minimum of 16 cores per server, regardless of the number of cores your server has.
- Core Packs: Licenses are sold in two-core packs, meaning that if you have a 24-core server, you will need 12 two-core packs to be fully licensed.
Example: Imagine you have a physical server with 20 cores. Microsoft requires a minimum licensing of 16 cores per server, meaning you must purchase at least 16 cores even though you have 20. To fully license your server, purchase 10 two-core packs for all cores.
Advantages of Core-Based Licensing:
- Flexibility in Scaling: Since licensing is based on physical cores, you can easily scale up your hardware without changing your licensing structure.
- Suitable for Virtual Environments: Core-based licensing is especially beneficial for organizations that run many virtual machines, as it covers all cores in the physical host.
Client Access Licenses (CALs)
Microsoft Server products often require Client Access Licenses (CALs) and server licenses. CALs allow users or devices to connect to the server.
Types of CALs:
- User CAL: A User CAL allows one user to access the server from multiple devices. This is ideal for employees who use multiple devices, such as laptops, tablets, and smartphones.
- Device CAL: A Device CAL allows multiple users to access the server from one device. This is a good fit for shared devices like those used in libraries or customer service stations.
Example: If you have 20 employees who each use multiple devices to connect to the server, it would make sense to purchase 20 User CALs. Alternatively, if you have 10 shared workstations accessed by different employees on different shifts, 10 Device CALs would suffice.
Considerations for Choosing CALs:
- User CALs are advantageous if most users access the server from multiple devices.
- Device CALs are suitable when you have shared workstations used by multiple people.
Per-Core vs. Per-User Licensing
Microsoft offers different licensing models to meet businesses’ diverse needs. The Per-Core and Per-User models are the most commonly used for Microsoft server licensing.
Per-Core Licensing:
- Used for licensing physical cores in servers.
- Suitable for environments with robust hardware and high-density virtualization.
Per-User Licensing:
- Applicable to users accessing software like SQL Server in a virtualized environment.
- Suitable for businesses where users need flexibility across devices without worrying about the underlying hardware.
Example Comparison: Consider a scenario where a business has a SQL Server deployment. The Per-Core licensing model will offer the flexibility needed to scale if the organization is highly virtualized with many physical cores. On the other hand, if employees need to access the SQL Server from multiple locations or devices, the Per-User model may be more economical.
Licensing for Virtualization Environments
Virtualization is a crucial component in today’s IT environments, and licensing must account for the complexity it introduces. Microsoft provides various options for server licensing in virtualized environments.
Core-Based Licensing for Virtual Machines (VMs):
- When running virtual machines, you must license all physical cores on the host server to cover multiple VMs.
- Microsoft offers Datacenter Edition for environments with extensive virtualization. It allows unlimited virtual instances, making it ideal for data centers.
Example: If you have a physical server with 16 cores and plan to run 10 virtual machines, using Windows Server Datacenter Edition would be the most cost-effective, allowing you to run unlimited VMs on that host.
Licensing Individual Virtual Machines:
- Microsoft also allows licensing per individual virtual machine, which is feasible for businesses with fewer virtual servers.
- The Standard Edition allows up to two VMs per physical server. If you need more VMs, you can purchase additional licenses.
Licensing for Cloud and Hybrid Environments
Microsoft also offers licensing models suitable for cloud and hybrid deployments, recognizing the industry’s shift toward cloud infrastructure.
Azure Hybrid Benefit:
- This program lets businesses use their existing on-premises licenses to cover virtual machines in Microsoft Azure, thereby saving costs.
- Azure Hybrid Benefit applies to Windows Server and SQL Server and allows companies to take advantage of cloud infrastructure without purchasing separate cloud licenses.
Example: If your organization currently has Windows Server data center licenses with Software Assurance, you can use the Azure Hybrid Benefit to move your on-premises servers to Microsoft Azure without incurring additional licensing costs for those servers.
Licensing Strategies for Cost Efficiency
Licensing can often be a major portion of IT budgets. Choosing the right server licensing model is critical for optimizing costs without compromising compliance or performance.
Strategies to Minimize Licensing Costs:
- Audit Your Environment: Conduct regular audits to understand how many cores, users, or devices need licensing. This prevents over-licensing or under-licensing.
- Choose the Right Edition: For environments with heavy virtualization, opt for Windows Server Datacenter Edition, which allows unlimited VMs and scales better.
- Use Azure Hybrid Benefits: If you are considering a move to the cloud, leveraging Azure Hybrid Benefits can significantly reduce costs.
- Mix and Match CALs: Sometimes, combining User CALs and Device CALs can be more economical, depending on usage patterns.
Example: Consider a company with 50 employees, each accessing a Windows Server from a laptop and a desktop. Purchasing User CALs would be more efficient, as users only need one license to access the server from multiple devices. However, if there were 20 shared devices in a production line accessed by multiple shifts, then Device CALs would be a better fit.
Software Assurance (SA)
Software Assurance is an add-on to Microsoft server licenses that provides various benefits, such as upgrade rights, license mobility, and training resources.
Key Benefits of Software Assurance:
- Upgrade Rights: Allows you to upgrade to the latest server software versions without buying new licenses.
- License Mobility: This enables licenses to be reassigned to different servers, which is beneficial in dynamic environments.
- Disaster Recovery: Provides rights for disaster recovery servers without additional costs, ensuring business continuity.
Example: If a company purchases Windows Server 2019 with Software Assurance, it can upgrade to Windows Server 2022 at no additional cost when it is released, ensuring it is always up-to-date with the latest features and security.
FAQ for Microsoft Server Licensing Models.
What is Per Core Licensing?
Licenses are required for each processor core in the server, ensuring accurate scalability.
How does Server & CAL licensing work?
You need a license for the server and a CAL for each user or device accessing it.
What is a Client Access License (CAL)?
A CAL allows users or devices to legally access services from the licensed server.
When is CAL required?
CAL is needed when clients, devices, or users connect to Microsoft servers.
What is a Virtualization Rights option?
Certain licenses allow you to run multiple virtual instances of Windows Server.
How does Per VM Licensing work?
You need a license for each virtual machine, typically for data centers.
What is Datacenter Licensing?
Allows unlimited virtual machines with a license for all physical cores on the server.
How is Server Licensing affected by cloud services?
Licensing models vary for hybrid or fully cloud-based setups, requiring a closer look at compliance.
What are External Connectors?
External Connectors provide access to users not covered by your internal licensing.
What is Active Directory Rights Management Services (ADRMS) Licensing?
Allows secure access and management of documents, providing specialized access control.
Can you mix licensing models?
Yes, you can combine licensing models to optimize access depending on your environment.
What is License Mobility?
License mobility allows certain licenses to be transferred between servers or the cloud.
How are Software Assurance Benefits linked to server licensing?
Software Assurance adds benefits like upgrades and support to your server licensing agreement.
What is an External Use License?
Provides rights for external users to access your licensed server services without individual CALs.
How does Microsoft Server Licensing impact virtual environments?
You must account for the number of virtual machines and core licenses in virtual environments.
