Cache control by adding record identification information to partial write request

A disk storage subsystem connected to a data processing unit, comprising:

• a disk unit having a plurality of records in which data used by said data processing unit are stored, each of said records having a record number;
• and
• a control unit including a cache memory for storing data to be stored into records of said disk unit, said control unit having record format information representative of record formats of records of said disk unit, including identification information indicating the record numbers and record lengths of records in the disk unit;
• wherein said control unit, in response to a partial write request having a record number for designating a record, controls data transfer from said data processing unit to said cache memory by referring to said record format information in said cache memory if data corresponding to the record designated by said partial write request do not exist in said cache memory;
• and notifies said data processing unit of a completion of said partial write request.

A disk storage subsystem connected to a data processing system, comprising:

• a disk unit having a plurality of records in which data used by said data processing unit are stored, each of said records having a record number;
• and
• a control unit including a cache memory for storing data to be stored into records of said disk unit;
• wherein said control unit, in response to a partial write request, issued from the data processing unit, having a record number and record format information that enables said control unit to recognize whether the record having the designated record number exists in said disk unit, controls data transfer from said data processing unit to said cache memory with referring to said record format information in said cache memory if data corresponding to the record having the designated record number do not exist in said cache memory, and notifies said data processing unit of a completion of said partial write request.

A disk storage subsystem connected to a data processing unit, comprising:

• a disk unit having a plurality of records, each of said records having a control field and at least another field for storing data used by said data processing unit, wherein said control field includes a record number for identifying the record and field length of said at least another field;
• and
• a control unit including a cache memory for storing data to be stored into records of said disk unit and having record format information representative of record formats of records of said disk unit, including identification information indicating the record numbers and record lengths of records in the disk unit;
• wherein said control unit, in response to a partial write request having a record number and field information for identifying a specific field of the record designated by said record number, controls data transfer from said data processing unit to said cache memory by referring to said record format information if data corresponding to said specific field identified by said field information in the record designated by said record number do not exist in said cache memory;
• and notifies said data processing unit of a completion of said partial write request.

A disk storage subsystem connected to a data processing system, comprising:

• a disk unit having a plurality of records in which data used by said data processing unit are stored, each of said records having a control field and at least another field for storing data used by said data processing unit, wherein said control field includes a record number for identifying the record and field length of said at least another field;
• and
• a control unit including a cache memory for storing data to be stored into records of said disk unit;
• wherein said control unit, in response to a partial write request having (a) a record number, (b) field information for identifying a specific field other than a control field of the record designated by said record number, and (c) record format information that enables said control unit to recognize whether the record having the designated record number exists in said disk unit, controls data transfer from said data processing unit to said cache memory by referring to said record format information if data corresponding to the record having the designated record number do not exist in said cache memory, and notifies said data processing unit of a completion of said partial write request.