Copyback(回拷), 這不是甚麼很創新的設計. 事實上它存在了非常久, 是一種Hot Spare(HSP)的其他使用方式. 姑且可以看看他的粗粗淺說明, 以便了解他是做甚麼用的: The procedure used to copy data from a source drive of a virtual drive to a destination drive that is not a part of the virtual drive. The copyback operation is often used to create or restore a specific physical configuration for a drive group (for example, a specific arrangement of drive group members on the device I/O buses). The copyback operation can be run automatically or manually. Typically, a drive fails or is expected to fail, and the data is rebuilt on a hot spare. The failed drive is replaced with a new drive. Then the data is copied from the hot spare to the new drive, and the hot spare reverts from a rebuild drive to its original hot spare status. The copyback operation runs as a background activity, and the virtual drive is still available online to the host.
簡單來說, copyback可以重建原來的DG設定. 當然, 他需要依賴HSP的使用, 不管是Dedicated(DHSP)或著Global(GHSP). Copyback預設是自動啟用的, LSI的SSD Guard也是基於copyback去實現的.
