摘要 |
In a previous storage apparatus, differential JNLs are reflected in order of the update numbers, to the data volumes thereof. If a first storage apparatus is suspended, it is determined which is newer: the update number which the journal recently reflected in a second storage apparatus or the update number reflected in a third storage apparatus. In the newer storage apparatus having the newer update number, it is determined whether one or more JNLs from the journal having the update number next to the update number which is not determined to be the newer to the journal having the update number determined to be the newer exist, or not. If the result of the determination is positive, from the newer storage apparatus to the previous storage apparatus which is not the newer of the second and the third storage apparatuses, one or more differential JNLs are copied.
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