VMware vSphere Update Manager (VUM) is software for automating patch management.
vSphere Update Manager works in conjunction with vSphere Distributed Resource Scheduler (DRS) to provide non-disruptive host patching for clusters. VUM works with vSphere DRS to put hosts in maintenance mode one by one and migrates live virtual machines (VMs) to other hosts while patching. VUM can also be used to manage vSphere versions, install and update third-party ESX/ESXi host extensions and upgrade virtual appliances, VMware Tools and virtual machine hardware.
VUM requires a connection to vCenter Server and must be registered with vCenter Server to function.