An information processing system includes a plurality of computers and a management device. Each computer executes a program to generate virtual machines and a plurality of virtual operating systems. The managing device executes migration to migrate virtual operating systems executed on one of the plurality of computers to another computer among the plurality of computers. The managing device is configured to identify a plurality of virtual operating systems to be executed on a same virtual machine upon the migration by detecting a plurality of different virtual operating systems executed on the same virtual machine, each of the plurality of different virtual operating systems running an application program which communicates with other application program running on another one of the plurality of different virtual operating systems, and cause the other computer to generate the virtual machine to which the identified virtual operating systems are to be migrated in advance.