A method for assuring consistency between a primary volume and a remote secondary volume wherein a host CPU manages track-to-track transfers using loosely-coupled, storage control unit mediated data paths. The method includes initial volume synchronization in which concurrent updates to primary tracks...http://www.google.de/patents/US6578120?utm_source=gb-gplus-sharePatent US6578120 - Synchronization and resynchronization of loosely-coupled copy operations between a primary and a remote secondary DASD volume under concurrent updating
