You can upgrade virtual machines to a higher level of compatibility and a higher version of VMware tools. After the upgrade, your VMs can take advantage of new hardware options and new features.
For a list of hardware features available to virtual machines with each ESXi hardware compatibility setting, see Hardware Features Available with Virtual Machine Compatibility Settings.
To determine whether your virtual machines are compatible with a new version of ESXi, see Virtual Machine Compatibility.
VMware Tools Upgrade
The first step in upgrading virtual machines is to upgrade VMware Tools. Installing VMware Tools is part of the process of creating a new virtual machine. If you are installing VMware Tools in multiple virtual machines with Windows guest operating systems, you can automate its installation and specify options for the components to include or exclude. For information about installing, upgrading, and configuring VMware Tools, see the VMware Tools User Guide.
If the virtual machines do not have VMware Tools installed, you can use the VMware Tools upgrade procedure to install VMware Tools. After you install or upgrade VMware Tools, upgrade the virtual machine compatibility.
Virtual Machine Compatibility Upgrade
VMware offers the following tools for upgrading virtual machines:
Requires that you perform the virtual machine upgrade one step at a time, but does not require vSphere Update Manager.
In the vSphere Client, you can upgrade virtual machines manually, or schedule upgrades.
Use this procedure to upgrade one or more virtual machines to the latest supported virtual hardware version immediately.
Schedule VM Upgrades
Use this procedure to schedule an upgrade of one or more virtual machines at the next reboot of the virtual machine, and choose from all supported compatibility level upgrades.
vSphere Update Manager
Automates the process of upgrading and patching virtual machines, ensuring that the steps occur in the correct order. You can use Update Manager to directly upgrade virtual machine hardware, VMware Tools, and virtual appliances. You can also patch and update third-party software running on the virtual machines and virtual appliances. See the Installing and Administering VMware vSphere Update Manager documentation.
Do not use vmware-vmupgrade.exe to upgrade virtual machines.
Upgrading virtual machine hardware is a heavyweight operation that might cause some applications or the operating system to stop working properly.