VMware ESXi

VMware ESXi Free Restrictions and Limitations

VMware ESXi is one of the market leaders of virtualization solutions and VMware ESXi is a well-known type 1 hypervisor that is highly respected by IT specialists. More and more people and companies are deploying ESXi servers in their environment to run virtual machines. 

ESXi Hypervisor is provided as part of VMware vSphere which, in turn, is equipped with different license options for each edition. Each edition of VMware vSphere has its own price but VMware also provides a free version of ESXi. Today's blog post explores the free features of VMware ESXi as well as the restrictions and limitations that await when using this ESXi hypervisor version.

Apply the VMware ESXi Free License

Download the ISO image of the ESXi installer from the VMware website, for which you must have a VMware account. Certain versions of the installer file (for example, 6.7) from the ESXi hypervisor are the same for all editions. A different set of features and capabilities is defined after applying the appropriate license. After installing ESXi, the full-featured 60 day evaluation period begins. Uses all features available for the Enterprise Plus edition during the 60 day evaluation period. If applying a license before the evaluation period ends, you can only use the features permitted by the license. 

If 60 days have passed and no licenses have been applied, then all advanced features are locked, running the VM continues to run but cannot start turning off the VM. The ESXi host that is connected to the vCenter Server is disconnected in this case. Implement a license (free or paid) to make the VMware ESXi server work again.

After downloading the installer and receiving the free ESXi license key, you can install the ESXi server according to the process described in this blog post. After installing the ESXi server, open a web browser and enter the IP address of the ESXi host to open VMware Host Client. Enter root as the username and password specified during ESXi installation to enter. In the left panel (Host Navigator) select Host> Manage, then select the Permissions tab.

As seen in the screenshot above, a host is running in evaluation mode. In the current example ESXi was installed on January 18 and the expiration date is March 19. A complete list of features available for the 60-day evaluation period is displayed on this page in the features section. The license key is displayed as 25 zeros in this case. Let's apply the free VMware ESXi license key. Click Set License and enter the key (25 symbols). Click the Check License button, and if the license key is valid, click Set license.

Now the type of license has changed from Evaluation mode to VMware vSphere 6 Hypervisor. The string "Up to 8 virtual directions in SMP" is displayed in the feature column. SMP means Symmetric Multi-Processing - a feature that defines the number of cores that hosts can schedule VMs to use at once (8 core / virtual processors if using a free license). The expiration date is changed to Don't i  VMware ESXi.

How to Check for Features Available with a Free VMware License

The first visual difference to notice is shown in the screenshot above. If you want to see more detailed license information, use the console. Make sure SSH access is enabled in ESXi settings. Enter the following command to see available licenses and features, vim-cmd vimsvc / --show license
In the screenshot below you can see the output of this command for ESXi running in free mode and for ESXi running in evaluation mode. The list of available features is much longer for VMware ESXi servers running in evaluation mode.

List of Limitations for VMware ESXi Free

Now let's take a closer look at the restrictions when using ESXi server version 6.7 with a free license. Depending on the environment, some restrictions may not be too obvious to others while others may be critical:
  • No Official VMware Support
  • Max 8 vCPU per Each VM
  • Cannot be managed with vCenter
  • vStorage API Not Available

There is no Official VMware Support

There is no commercial technical support provided by VMware for ESXi for free. Ask for support from the VMware community, and if you are lucky, you can find a solution to solve the problem. While VMware commercial technical support functions 24x7 and usually provides answers in a short period of time, help in solving problems by the VMware community may take a little longer. VMware's commercial support also provides software enhancements.

Max 8 vCPU per Each VM

If creating a VM with more than 8 virtual processors (for example, VMs with 9 processors, one virtual core or VM with 5 virtual two core processors), the VM tends to fail to start ESXi for free, indicating an error "There is an inadequate license to complete this operation" . At the same time, with Evaluation or Enterprise Plus editions you can create VMs with up to 128 vCPU (virtual Central Processors Units) that are assigned to that VM. The 8 vCPU limit may not cause significant losses, unlike the following two restrictions with VMware ESXi.

Cannot be Managed with vCenter

The free version of the ESXi server cannot be managed with vCenter - a centralized server for managing hosts and virtual machines. If you try to add an ESXi host with a free license to vCenter Server, you can expect to get an error: "License not available to do the operation". Therefore, it cannot migrate the machine from one free ESXi host to another host and use the clustering feature, because vCenter Server is required to perform this operation. This is a significant loss if you plan to use multiple VMware ESXi hosts.

VStorage API Not Available

VMware provides a data protection framework called vStorage API (Application Program Interface) to allow virtual machine backups to be centralized at the host level. vStorage APIs allow third-party applications to make VM backups more efficient and release CPU, network and storage. ESXi Server Free Edition does not allow applications to interact with ESXi servers through the vStorage API, therefore, the VM cannot be supported from the free version of ESXi at the host level. 

The backup application will display an error message in this case. Back up the legacy VM that runs on the free version of the ESXi host that requires an agent installation on the guest operating system. This blog post explains why old backups are not recommended for backing up virtual machines.

CPU Physical Unlimited per Host

The free ESXi license allows using an unlimited number of physical processors for ESXi hosts (VMware vSphere Hypervisor). In the old version of ESXi, free licenses were restricted to using more than 2 physical processors. This processor is virtualized but is not copied in terms of hardware virtualization and is one of its main components VMware ESXi.

Unlimited Cores per CPU

Cores per physical CPU are not limited to free ESXi licenses. This feature allows rational use of hardware CPU performance. One CPU core can be used as one virtual processor or one virtual processor core for virtual machines.

Unlimited Physical Memory

Similar to the physical CPU and processor core, physical memory is not limited to ESXi servers that have free licenses. Along with unlimited CPUs and CPU cores, this feature allows to deploy powerful physical servers that contain 4, 6 or more multicore CPUs with large amounts of RAM, install ESXi, implement free licenses, and use many VMs (max. 8 vCPUs per VM).

There is no Expiration Date

Get a free ESXi license once, and feel safe knowing that the license never ends. This means that you can use the free version of ESXi server as long as you want. If you need to apply a commercial license, you can do it at any time without reinstalling the ESXi server. Just open the license option on the VMware ESXi host client from the VMware vSphere client and enter the new license.


VMware provides a loyal licensing policy and can plunge into the beautiful world of hardware virtualization with free VMware ESXi, also called VMware vSphere Hypervisor, according to VMware license requirements. Free VMware ESXi can be considered a good solution for small companies such as small shops and entrepreneurs, as well as for testing or learning purposes. 

The main disadvantage of using VMware ESXi for free is the inability to use the vStorage API and, as a result, uses native backup applications to back up host-level VMs, and lack access to centralized management with VMware vCenter Server. Despite limitations, using ESXi free in a production environment is not prohibited by the license agreement. Read more on blog posts about VMware ESXi editions and licenses.