Microsoft Per Core licensing rules
The Per Core licensing model is used by many Microsoft server products, such as SQL Server and BizTalk Server. It's useful when counting users or devices connecting to the software is difficult, often for internet-facing software.
Therefore, the Per Core licensing model is commonly used for enterprise software like Microsoft SQL Server.
The licensing rules for on-premise installations of these products and the cloud installations are separate. The cloud licensing rules follow Bring Your Own License (BYOL). For more information, see Licensing rules for BYOL and BYOS.
- Licensing by physical cores, also known as licensing by physical hosts
- Licensing by individual virtual machines
You can either allocate manually, or the Software Asset Management application can automatically select the most cost-effective licensing option based on optimization criteria. The number of core licenses required depends on whether you’re licensing the physical server based on its physical cores or licensing individual virtual machines.
Licensing by physical cores
| Rule | SQL Server Standard | SQL Server Enterprise |
|---|---|---|
| Applicability | Not allowed 注: Only allowed to be licensed through individual virtual machines. |
The number of licenses required equals the number of physical cores on the licensed server. The physical cores on servers are equal to |
| Min licenses required | Not allowed 注: Only allowed to be licensed through individual virtual machines. |
4 licenses per physical processor |
| Virtualization rights | Not allowed 注: Only allowed to be licensed through individual virtual machines. |
|
| Failover rights | Not allowed 注: Only allowed to be licensed through individual virtual machines. |
For each server operating system environment (OSE) licensed with SQL Server subscription licenses covered by active Software Assurance, you can use the following passive replicas ahead of a failover event:
|
| Components services licensing | Not allowed 注: Only allowed to be licensed through individual virtual machines. |
The software components of a single SQL Server license can't be separated. An OSE running any of the licensed components of SQL Server requires its own license. For more information about SQL Server components, see Editions and supported features of SQL Server 2022. |
Technologies like VMware vMotion, which enables live migration of virtual machines across all hosts, and host affinity, which helps lock virtual machines to hosts within a cluster, manage the movement of virtual machines across hosts. To understand more about cluster virtualization technology and its support on the Software Asset Management application, see Understanding your cluster infrastructure.
According to Microsoft licensing rules, if a virtual machine with a Microsoft product like Windows Server installed is hosted on one server but can potentially migrate to another, the destination server must be licensed as if the virtual machine is already running on it.
Licensing by virtual machines
The Software Asset Management application supports licensing by individual virtual machines rules, introduced by Microsoft in 2022.
| Rule | SQL Server Standard and SQL Server Enterprise |
|---|---|
| Required number of licenses | Equals the number of virtual cores on the virtual machine The virtual cores on servers are equal to |
| Min licenses required | 4 licenses per virtual machine |
| Software assurance or subscription license 注: The option to license by virtual machine is only available with software assurance or a subscription license. |
Required |
| License mobility within Server farms (Software assurance benefit) 注: Licenses can be reassigned within the same server farm as often as needed. The 90-day rule applies only when moving to another server farm or
cloud provider. |
Supported |
| Component services licensing | The software components of a single SQL Server license can't be separated. An OSE running any of the licensed components of SQL Server requires its own license. For more information about SQL Server components, see Editions and supported features of SQL Server 2022. |
| Failover rights | For each server OSE licensed with SQL Server subscription licenses or licenses covered by active software assurance, use the following passive replicas ahead of a failover event:
|