摘要 |
A backing-up apparatus, upon receiving an instruction to execute backing up, allocates a storage area to store a snapshot to be produced to each time point indicated by the instruction. When the original data is updated after the time point indicated by the instruction, it is checked that the original data corresponding to the place to which the updating has been executed at a time point immediately before the time point indicated by the instruction is stored in the storage area allocated as the storage area to store the latest snapshot produced for the immediately previous time point. When it has been confirmed that the original data is not stored, the original data immediately before the updating corresponding to the place to which the updating has been executed is stored in only the storage area to store the latest snapshot.
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