| 摘要 |
<p>This storage device is designed to compress write data written into a volume from a host computer by a cache unit and adds the compressed data as a postscript to a final storage medium, and is characterized by, when executing garbage collection, offloading part of the processing thereof to the cache unit. The storage device starts the garbage collection processing at a point in time when a write area within a page in the final storage medium is running short. In the garbage collection processing, the entire page in the final storage medium is staged to the cache unit, and in the cache unit, only the latest updated data of the staged data is mapped to the volume. A storage controller brings the entire area of the page to be subjected to the garbage collection into an unused state, and writes back the data on the cache unit, which has been mapped to the volume, to the final storage medium in order from the top of the page.</p> |
