| 摘要 |
PURPOSE:To attain the data recovery without using an auxiliary storage device by reading an effective data from an access volume to reconstitute an idle block management table thereby deleting a data not guaranteed on the idle block management table. CONSTITUTION:An idle block management reconstituting means 52 reconstitutes the idle block management information from directory information discriminated as effective information. That is, the idle block management information is reconstituted by start/stop addresses 21, 22 of the directory section 20, a directory maximum block address 11 of a volume header 10, and a data maximum block address 12. An ineffective data deleting means 53 deletes the ineffective data from the reconstituted idle block management information and clears the area in the range shown in the idle block management. An effective directory clearly indicating means 54 indicates clearly the effective directory realized by the means above. Thus, the data is recovered without using the auxiliary storage device for the direct access volume. |
