Storage control device, computer-readable recording medium, and method thereof

A non-transitory computer-readable recording medium having stored therein a program for causing a computer to execute a digital signature process comprising:

• obtaining an access request having a random characteristic which gives instructions to access a storage device for storing information by a random access, or an access request having a sequential characteristic which gives instructions to access the storage device by a sequential access;
• comparing a threshold with a ratio of a number of commands issued to the storage device corresponding to the access request having the random characteristic to a number of commands issued to the storage device corresponding to the access request having the sequential characteristic;
• generating a command to which first identification information for instructing the storage device to determine an execution order of commands issued to the storage device has been assigned or a command to which second identification information for instructing the storage device to execute commands in an order in which the storage device received the commands has been assigned, in accordance with a result of a comparison between the threshold and the ratio of issued commands;
• issuing the generated command to the storage device;
• measuring a time from issuance of the command to a response from the storage device when the obtained access request has a random characteristic;
• and
• adjusting the threshold in accordance with a result of a comparison between a currently measured time obtained by the measurement and a most recent previous measured time obtained by the measurement.

A method of controlling a storage, the method comprising:

• obtaining an access request having a random characteristic which gives instructions to access a storage device for storing information by a random access, or an access request having a sequential characteristic which gives instructions to access the storage device by a sequential access, by using a computer;
• comparing a threshold with a ratio of a number of commands issued to the storage device corresponding to the access request having the random characteristic to a number of commands issued to the storage device corresponding to the access request having the sequential characteristic, by using the computer;
• generating a command to which first identification information for instructing the storage device to determine an execution order of commands issued to the storage device has been assigned or a command to which second identification information for instructing the storage device to execute commands in an order in which the storage device received the commands has been assigned, in accordance with a result of a comparison between the threshold and the ratio of issued commands, by using the computer;
• issuing the generated command to the storage device, by using the computer;
• measuring a time from issuance of the command to a response from the storage device when the obtained access request has a random characteristic, by using the computer;
• and
• adjusting the threshold in accordance with a result of a comparison between a currently measured time obtained by the measurement and a most recent previous measured time obtained by the measurement, by using the computer.