Patent ID: 8886843

Claim:
A storage apparatus, comprising: a communication control processor, configured to control communications with an external apparatus; and a plurality of main processors, each main processor configured to perform an input/output (I/O) process on a storage drive according to an I/O request received from the external apparatus, wherein the storage apparatus: manages data to be stored or data that has been stored in the storage drive in accordance with a Count Key Data (CKD) format, which includes a count (C) field, a key (K) field, and a data (D) field; distributes the I/O process to a plurality of the main processors in units of data fields on a basis of operation rates of the respective main processors, wherein the operation rate of a main processor is a percentage of a given period of time that the main processor was operating, information of the fields forming a record of data targeted by the I/O process, and an I/O load indicator, which is a load indicator of the I/O process currently running on each of the main processors; and does not distribute the I/O process to the plurality of main processors when the I/O load indicators of all the main processors other than the main processor receiving the I/O request are not zero, and when the I/O load indicator of the main processor receiving the I/O request is equal to or less than the I/O load indicators of all the other main processors.