Prior to migrating a guest operating system (OS) from a first to a second server, transmissions to the guest OS are looped back

摘要

An administrative manager (10, Fig. 1) connected to a plurality of servers 20, each including a virtual machine environment in which a host OS 30 and a guest OS 40 are operable as virtual OS, performs the following processes. When an operator issues an instruction to migrate the guest OS from a migration source server (alpha) to a migration target server (beta), a connection target server (gamma) connected by a virtual connection (i.e. a tunnel) to the migration source server is specified (S1, Fig. 8 and Fig. 10C). Connection information necessary for a virtual network connection between the connection target server and the migration target server is then acquired (S2, S3 of Fig. 8 and Figs. 10B and 10A). Then, before the guest OS is migrated, in the connection target server, transmission data to the migration guest OS is set to be looped back (S4 of Fig. 8 and Fig. 13A). After the guest OS is migrated, the network setting is made on the migration target server (Fig. 14A and Fig. 15B) and the connection target server (Fig. 14B and Fig. 15A) so as to enable the mutual virtual network connection and the loopback is cancelled. This reduces interruption of service.