Tape device and method of controlling tape device

1. A tape device comprising:

a memory; and

a processor coupled to the memory, wherein the memory stores management information in which an identifier of a medium and a data volume further recordable on the medium are in association with each other and

the processor executes a process comprising:

measuring a data volume written in the medium or a data volume read out of the medium according to execution of an input/output command;

calculating a data volume recorded on the medium from a total of the data volume measured at the measuring;

acquiring a recorded medium length, which represents a length of the medium up to an end position of the data written in or read out of the medium by the execution of the input/output command from a beginning position of the medium, the length of the medium being measured using a position of a head to the medium, from a drive to which the medium is mounted without loading the medium to the drive;

calculating the data volume further recordable on the medium, based on the recorded data volume and the recorded medium length; and

updating the management information stored in the memory with the data volume further recordable on the medium calculated at the calculating, wherein

the measuring includes measuring the data volume written in the medium or the data volume read out of the medium whenever the input/output command is executed.

2. The tape device according to claim 1 ,

wherein, when finish information, which represents end of writing of data, is written in or read out by the execution of the input/output command, the calculating includes calculating a recorded data volume per length of the medium from the recorded medium length and the recorded data volume, and calculates the data volume further recordable on the medium from the calculated recorded data volume per length of the medium and a length of a non-recorded portion of the medium.

3. The tape device according to claim 1 , wherein the process further comprising:

determining whether the medium is an unused one based on presence or absence of information containing the identifier of the medium when the medium is mounted; and

generating the management information in which the identifier of the medium and the data volume further recordable on the medium are in association with each other when the determining determines that the medium is the unused one.

4. The tape device according to claim 3 ,

wherein the determining includes reading the identifier of the medium and searching for the management information that matches the read identifier of the medium when it is determined that the medium is not the unused one, and

the updating includes updating the management information with the data volume further recordable on the medium calculated at the calculating when there is the management information that matches the read identifier of the medium as a result of the searching at the determining.

5. The tape device according to claim 4 ,

wherein the generating includes generating the management in which the identifier of the medium and the data volume further recordable on the medium are in association with each other when there is no management information that matches the read identifier of the medium as a result of the searching at the determining.

6. The tape device according to claim 1 , wherein the process further comprising:

reading the management information from the storage unit; and

transmitting the read management information to an information processor when an acquisition request of the management information is received from the information processor.

7. A method of controlling a tape device, the method comprising:

measuring a data volume written in a medium or a data volume read out of the medium according to execution of an input/output command;

calculating a data volume recorded on the medium from a total of the data volume measured;

acquiring a recorded medium length, which represents a length of the medium up to an end position of data written in or read out of the medium by the execution of the input/output command from a beginning position of the medium, the length of the medium being measured using a position of a head to the medium, from a drive to which the medium is mounted without loading the medium to the drive;

calculating a data volume further recordable on the medium based on the recorded medium length and the recorded data volume; and

updating management information stored in a storage unit which stores the management information in which an identifier of a medium and a data volume further recordable on the medium are in association with each other with the data volume further recordable on the medium which is calculated at the data volume calculating, wherein

the measuring includes measuring the data volume written in the medium or the data volume read out of the medium whenever the input/output command is executed.