Tape device and method of controlling tape device

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.