Before running a migration from vCenter Server that runs on Windows, or upgrading vCenter Server Appliance that use an external Update Manager, you must download and run the VMware Migration Assistant on the source Windows physical server or the Windows virtual machine where Update Manager runs. The VMware Migration Assistant facilitates the migration of the Update Manager server and database to the vCenter Server Appliance 6.5.

Alternatively, if you plan to perform the CLI method for upgrading your vCenter Server Appliance or migrating your vCenter Server that runs on Windows, you can skip this procedure, and add the source.vum section section and run.migration.assistant subsection to your JSON template. For information about the CLI upgrade or migration configuration parameters, see the vSphere Upgrade documentation.

Caution: It is important to run the VMware Migration Assistant on the source Update Manager machine before migrating other of the vCenter Server components.


  • Download the vCenter Server Appliance Installer. For more information, see the vSphere Installation and Setup documentation.
  • Log in to the source Update Manager machine as an administrator.


  1. From the vCenter Server Appliance installer package, copy the migration-assistant folder to the source Update Manager machine.
  2. From the migration-assistant directory, double-click VMware-Migration-Assistant.exe, and provide the vCenter Single Sign-On administrator password.
    Note: Leave the Migration Assistant window open during the migration process. Closing the Migration Assistant causes the migration process to stop.
    The VMware Migration Assistant runs pre-upgrade checks and prompts you to resolve any errors it finds before starting the upgrade.


When the pre-checks are finished and any errors are addressed, your source Update Manager system is ready for the migration to the vCenter Server Appliance.

What to do next

Use VMware Migration Assistant to migrate vCenter Server and all its components to vCenter Server Appliance 6.5.