What can vSphere Update Manager (VUM) update?

vSphere Update Manager (VUM) is designed to streamline the patching and updating process for various components within a vSphere environment. The capability of updating not just ESXi hosts but also host extensions and virtual machine hardware makes it a comprehensive tool for maintaining the health and performance of a virtualized infrastructure.

When it comes to ESXi hosts, VUM can apply patches, perform upgrades, and manage compliance to ensure that workloads are running on the latest supported versions. Additionally, it has the functionality to update VMware Tools, which is crucial for optimizing the performance of guest operating systems, as well as virtual machine hardware compatibility levels, ensuring VMs can leverage new features and enhancements.

This holistic approach towards updates enhances overall system reliability and performance, making it a versatile component of managing a VMware environment. This explains why the answer accurately reflects the extent of VUM's capabilities in dealing with ESXi hosts, their extensions, and virtual machine hardware, thus ensuring a robust and up-to-date virtualization platform.