DATA STORAGE DEVICE, AND SAVING METHOD OF LOG DATA

PROBLEM TO BE SOLVED: To save detailed log data without disturbing a recording/reproducing operation of data as an original operation in a data storage device. SOLUTION: The data storage device stores data in a recording medium 10, creates log data, and saves it in a nonvolatile memory 8. The data storage device sets priority to execute a normal processing of recording and/or reproducing data in the recording medium 10 in preference to log transfer processing of transferring and saving the log data in the nonvolatile memory 8, temporarily saves the created log data in a volatile memory 7 accessible faster than the nonvolatile memory 8 during executing the normal processing, and transfers and saves at least a part of the log data saved in the volatile memory 7 in the nonvolatile memory 8 during executing the log transfer processing. COPYRIGHT: (C)2007,JPO&INPIT