VMware regularly releases patches and updates to provide bug fixes so that it can address security vulnerabilities or add new features. Regularly patching an environment is important to the security and stability of the environment.

VMware vSphere Update Manager (VUM) is an optional vCenter component when it is installed on Windows, and it provides the patching and upgrading of ESXi hosts, VMware Tools, and VMware Guest Hardware. VUM ensures that compliance is maintained through patch and upgrade baselines. VUM also allows for the remediation of hosts or virtual machines that are not in compliance with the configured baselines.

VUM must be deployed on a Windows server, and it requires a supported database, either embedded or external. The VUM architecture is shown in the following diagram:

There is a one-to-one relationship between VUM and vCenter Servers. VUM 6.x is fully integrated into the vSphere Web Client.

VUM is always installed in an embedded fashion with the VCSA.