Patent ID: 6961832

Claim:
In a computer system which has a first computer, a second computer connected to said first computer via a communication line, a first storage apparatus connected to said second computer via a fixed length access interface and storing data in a fixed-length block format used by said second computer, and a second storage apparatus connected to said first computer, a method for processing data stored in said first storage apparatus to said first computer comprising the steps of: requesting, from said first computer to said second computer via said communication line, to send data stored in said first storage apparatus in said fixed-length block format to said first computer via the communication line; reading by using said second computer, in response to said request, data in said fixed-length block format from said first storage apparatus via said fixed length access interface and transferring by using said second computer said read data in said fixed length block format to said first computer via the communication line; converting, in said first computer, said transferred data in said fixed-length block format to data in variable-length block format; processing said converted data in said first computer; making volume information for accessing data stored in said first storage apparatus, in said first computer; checking whether data to be read is stored in said first storage apparatus or not based on said volume information by using said first computer; and reading data from said second storage apparatus if the data to be read is not stored in said first storage apparatus by said first computer.