Abstract: The current document is directed to methods and subsystems that validate migration of a virtualized subsystem from a first implementation and/or version to a second implementation and/or version carried out by a semi-automated or automated migration process. Virtualized-subsystem migrations allow a distributed computer system to access new and improved facilities and capabilities provided by a new virtualized-subsystem implementation and/or version. However, there are risks associated with semi-automated and automated migration processes. Independent validation of a migration by the currently disclosed methods and systems ameliorates these risks.