VMware vSphere Update Manager Download Service (UMDS) is an optional module of vSphere Lifecycle Manager. UMDS downloads software metadata, software binaries, and notifications that might not otherwise be available to vSphere Lifecycle Manager.
For security reasons and deployment restrictions, vSphere, including vSphere Lifecycle Manager, might be installed in a secured network that is disconnected from other local networks and the Internet. vSphere Lifecycle Manager requires access to patch information to function properly. If you are using such an environment, you can install UMDS on a computer that has Internet access. UMDS downloads upgrades, patch binaries, and patch metadata, and then you can export the downloads to a portable media drive so that they become accessible to vSphere Lifecycle Manager. If the server on which vCenter Server is installed has no Internet access, but is connected to a server that has Internet access, you can automate the export process and transfer files from UMDS to the vSphere Lifecycle Manager depot by using a Web server on the machine on which UMDS is installed.
UMDS is available for installation only on Linux-based operating systems. Installing UMDS on a Windows machine is no longer supported. Administrator access is not a requirement for downloading patches with UMDS that runs on Linux. The machine on which you install UMDS must have Internet access.
UMDS 8.0 supports patch recalls and notifications. A patch is recalled if the released patch has problems or potential issues. After you download patch data and notifications with UMDS, and export the downloads so that they become available to vSphere Lifecycle Manager, vSphere Lifecycle Manager deletes the recalled patches.
You can use UMDS to download updates that are packaged and distributed components, but it also works with legacy bulletins.
Compatibility Between UMDS and vSphere Lifecycle Manager
UMDS must be of the same version as vSphere Lifecycle Manager. For example, vSphere Lifecycle Manager 8.0 is compatible and can work only with UMDS 8.0. If you are using vSphere Lifecycle Manager of an Update release version, UMDS must be of the same Update release version.