| 摘要 |
PURPOSE:To prevent such trouble that check data can not be read because of the occurrence of a read error by constituting a data file of a source file consisting of data equal to each other and a backup file. CONSTITUTION:The data file is constituted of home directories 11, 21 to manage the whole data file, the source file 1 consisting of the data equal to each other, and the backup file 2, and the home directory 21 is used for backing up the home directory 11. When the check data is read, at first, the source file 1 is read preferentially, and only when the read error occurs at the time to read the source file 1, the backup file 2 corresponding to a part where the read error occurred is read. Thus, even if the read error occurs, such the trouble that the check data can not be read is prevented. |
