Patent ID: 7694092

Claim:
A storage system comprising at least one random storage device which constitutes a storage device of a type able to perform high-speed random access processing, and in which the at least one random storage device comprises a volume group and a journal volume, and the volume group containing a volume pair configured from a primary volume and secondary volume, and which whenever data is received from a host device, writes the received data in the primary volume, produces a journal which contains a write sequence of the data written in the primary volume and the data, and writes the journal in the journal volume, wherein the storage system comprises: a plurality of sequential storage devices that constitute a storage device of a type that is able to perform high-speed sequential access processing but is unable to perform high-speed random access processing, a backup unit that writes a plurality of journals accumulated in the journal volume in at least one of the plurality of sequential devices, and a restore unit that, based on the write sequence recorded in each of the plurality of journals that are recorded in at least one of the plurality of sequential devices, restores the data of the journals stored in the primary volume to the secondary volume of the primary volume or a volume related to the secondary volume, wherein the volume groups exist in plurality, and the backup unit controls backup in response to a comparison of the threshold value of each of the plurality of volume groups and a prescribed type value pertaining to the volume groups, and wherein a checkpoint is written in the journal volume at a prescribed moment, and the prescribed type value constitutes the number of checkpoints of the volume group correspondent to the value which have not been reflected in the sequential device.