Patent ID: 7363445

Claim:
A method of backing up data stored on a first information processing unit, using plural second information processing units connected to a network, comprising the steps of: sending autonomously a first message from the first information processing unit to the plural second information processing units, the first message inquiring as to a possibility of backing up the data stored on the first information processing unit to the plural second information processing units; receiving second messages at the first information processing unit from said plural second information processing units that responded to the first message, said second messages containing information as to the possibility of backing up the data stored on the first information processing unit; creating a first table on the basis of the second message by the first information processing unit, the first table managing at least information relating to the plural second information processing units capable of backing up the data, and retaining the first table at the first information processing unit; distributing the data stored on the first information processing unit as backup data to selected second information processing units as recipients of the backup data, said selected second information processing units being selected by the first information processing unit from the first table by comparing an amount of data each of said second information processing units is capable of backing up to a total amount of the data on the first information processing unit to be backed up, and by sending portions of the backup data to the selected second information processing units based upon the amount of data each selected second information processing unit is capable of backing up; creating a second table for managing information including an address of each of the selected second information processing units which is selected by the first information processing unit as a recipient of the backup data, and retaining the second table at the first information processing unit; sending a third message by the first information processing unit referring to the second table, said third message requesting restoration of the backup data to the first information processing unit by requesting transfer of the backup data portions from the selected second information processing units, each of which was the recipient of the backup data portions; receiving, by the first information processing unit, the backup data portions sent from the selected second information processing units; and storing the received backup data portions according to mapping information retained in the first information processing unit to restore the data stored at the first information processing unit.