Backup system

A backup system for protecting backup data, the backup system comprising a backup server having a backup management data for managing a copy number and a backup acquisition date and time for each backup image, and a storage system, the storage system comprising:

• a data volume that stores data accessed by a business server;
• a backup image volume that stores a plurality of backup images at different time points of the data volume;
• a primary usage volume that stores an oldest backup image among the plurality of backup images;
• a backup management volume that stores a copy of the backup management data of the backup server;
• an access volume having a volume ID for reading a backup image, of the plurality of backup images, from the backup server;
• and
• a data protection area including at least one volume having an internal volume ID instead of the volume ID for reading from the backup server,
• wherein the oldest backup image stored in the primary usage volume and an entry including the backup acquisition date and time corresponding to the oldest backup image stored in the primary usage volume in the backup management data stored in the backup management volume are sequentially stored in the volume of the data protection area using the internal volume ID of the volume of the data protection area, and
• wherein the backup image stored in the data protection area and the access volume are associated, and the backup image in the data protection area is provided to the backup server.