US Patent 11474732 Security system, host system, and backup method

Backup data equivalent to the maximum number of generations to be held can be secured even when backup data is locked. When locking of prohibiting overwrite of one or more storage areas is performed, a backup server prepares a new backup management table and uses the backup management table and an archive management table, which is the past backup management table, to store the backup data equivalent to the maximum number of generations to be held into a storage system.