Virtual storage machine (VSM) can be used as part of Virtual Storage Scale Out (VSSO) functionality.
VSSO is, at its core, clustering pools of resources to enable growth without introducing complexity. VSSO provides unified management via Hitachi Ops Center for all of the resources in the cluster, monitoring, trending, and reporting for those resources, and nondisruptive migrations from resource to resource should the need arise.
In this nondisruptive migration operation, you can treat a VSM as a single storage image. You can move volumes nondisruptively by GAD Volume Migration based on volume access frequency. Virtual storage machines are used to achieve continuous access to data for global-active device volumes, for scale-out with Virtual Storage Scale Out, and for data migration.