Data backup method and system

A disk array system comprising:

• a first storage region used as an external storage by a computer;
• a second storage region for storing management information for said first storage region;
• and
• a processor for making said first storage region and said second storage region be associated with each other based on a command from said computer, and storing information about said first storage region and information received from said computer in said second storage region.

A disk array for use in a computer system having a computer and said disk array comprising:

• a plurality of storage regions used by said computer as an external storage;
• and
• a processor which executes a disk array control program causing the disk array to perform the steps of:
• receiving from said computer a backup command accompanied by information about a first storage region having stored therein data to be backed up within said disk array and information about a second storage region into which said data to be backed up is to be stored as backup data within said disk array,
• backing up said data of said first storage region into said second storage region in response to said backup command,
• receiving from said computer at least said information about said second storage region and information about backup of said first storage region, and
• storing at least said information about said second storage region and said information about backup of said first storage region sent as above into a storage region different from said second storage region within said disk array so that both said information can be stored as management information for said backup data, and to be associated with said backup data.