ESXi hosts are licensed with vSphere licenses. Each vSphere license has a certain capacity that you can use to license multiple physical CPUs on ESXi hosts.
Starting with vSphere 7.0, one CPU license covers up to 32 cores. If а CPU has more than 32 cores, you need additional CPU licenses.
When you assign a vSphere license to a host, the amount of capacity consumed is determined by the number of physical CPUs on the host and the number of cores in each physical CPU. vSphere Desktop that is intended for VDI environments is licensed on per virtual machine basis.
To license an ESXi host, you must assign it a vSphere license that meets the following prerequisites:
- The license must have sufficient capacity to license all physical CPUs on the host.
- The license must support all the features that the host uses. For example, if the host is associated with a vSphere Distributed Switch, the license that you assign must support the vSphere Distributed Switch feature.
If you attempt to assign a license that has insufficient capacity or does not support the features that the host uses, the license assignment fails.
If you use the licensing model with up to 32 cores, you can assign a vSphere license for 10 32-core CPUs to any of the following combinations of hosts:
- Five 2-CPU hosts with 32 cores per CPU
- Five 1-CPU hosts with 64 cores per CPU
- Two 2-CPU hosts with 48 cores per CPU and two 1-CPU hosts with 20 cores per CPU
Dual-core and quad-core CPUs, such as Intel CPUs that combine two or four independent CPUs on a single chip, count as one CPU.
After you install ESXi, it operates in evaluation mode for up to 60 consecutive days. An evaluation mode license provides all features of the highest vSphere product edition.
After you assign a license to an ESXi host, at any time before the evaluation period expires, you can set the host back to evaluation mode to explore the entire set of features available for the remaining evaluation period.
For example, if you use an ESXi host in evaluation mode for 20 days, then assign a vSphere Standard license to the host, and 5 days later set the host back to evaluation mode, you can explore the entire set of features available for the host for the remaining 35 days of the evaluation period.
License and Evaluation Period Expiry
For ESXi hosts, license or evaluation period expiry leads to disconnection from vCenter Server. All powered on virtual machines continue to work, but you cannot power on virtual machines after they are powered off. You cannot change the current configuration of the features that are in use. You cannot use the features that remained unused before the license expiration.
Licensing ESXi Hosts After Upgrade
If you upgrade an ESXi host to a version that starts with the same number, you do not need to replace the existing license with a new one. For example, if you upgrade a host from ESXi 5.1 to 5.5, you can use the same license for the host.
If you upgrade an ESXi host to a major version that starts with a different number, the evaluation period restarts and you must assign a new license. For example, if you upgrade an ESXi host from 5.x to 6.x, you must license the host with a vSphere 6 license.
vSphere Desktop is intended for VDI environments such as Horizon View. The license use for vSphere Desktop equals the total number of powered on desktop virtual machines running on the hosts that are assigned a vSphere Desktop license.