| 摘要 |
<p>A storage device, a computer system, and a storage system are provided to realize fast rewriting in actual use by using a flash memory as a storage medium, reduce rewriting fatigue by reducing an erasure frequency, and realize high rewriting reliability. The storage device includes the flash memory as a main memory and a control circuit(74). The control circuit rewrites a part of the flash memories(75,76) by additionally writing update data to an empty area and nullifying original data, and automatically recovers the nullified area to the empty area during a standby state not accessed from an external device. Each flash memory has multiple erasure blocks(83,84) and each erasure block includes multiple page areas(79,80) which are an independent write unit. The controller performs backup for moving the data of an effective page area remaining in the erasure block including the nullified pager area to the erased empty area of other erasure blocks.</p> |
