| 摘要 |
<p>The invention relates to a method for providing on-line, real-time, transparent data migration from a first data storage system (14) to a second data storage system (16). The second data storage system is interposed between a host (12) and the first data storage system. A data map (24) identifies data elements stored on the second data storage system and corresponding data elements copied from the first to the second data storage system. In response to a host data request, the second data storage retrieves the data if stored therein. Otherwise, the second data storage system retrieves the data from the first data storage system, writes the data to itself and updates the data map. When not busy servicing requests, the second data storage system copies data from the first to the second data storage device independently of any coupled host. <IMAGE></p> |
