If you have assigned a license key to an ESXi host, you can switch to evaluation mode to explore the full set of features that are available for the host..
- From the vSphere Client, select the host in the inventory.
- Click the Configuration tab.
- Under Software, click Licensed Features.
- Click Edit next to ESX Server License Type.
- Click Product Evaluation.
- Click OK to save your changes.
The host is in evaluation mode and you can explore the entire set of features for ESXi. If you have already used the host in evaluation mode, the time that remains in the evaluation period is decreased by the time already used. For example, suppose you have used the host in evaluation mode for 20 days and then assigned a vSphere Standard license key to the host. If you set the host back in evaluation mode, you can explore the entire set of features that are available for the host for the remaining evaluation period of 40 days. You can track the remaining days from the evaluation period of a host in the host's page in the vSphere Client.
After the evaluation period of the host expires, you receive a warning message, and the host cannot be connected to a vCenter Server system. All powered-on virtual machines continue to work, but you cannot power on any new virtual machines. You cannot change the current configuration of the features that are already in use. You cannot use the features that remained unused while the host was in evaluation mode.