| 摘要 |
A tape controller (105) that recovers data from a block (203b) of data stored on magnetic tape (109) that has been affected in part by uncorrectable errors such as tape blemishes (213). Upon receiving a request for the block of data, the controller causes a tape drive (108) to read the block from the tape. The controller stores the read data in a buffer memory (111) that is at least the size of the data block. When the tape drive encounters the affected data while reading the block of data, the controller clears the buffer memory and causes the drive to read the block in reverse. The controller again stores the read data in the buffer memory, in the order in which they are read. When the drive again encounters the affected data, the controller reverses the contents of the buffer memory and then causes the drive to read the block in forward. The controller once more stores the read data in the buffer memory, thereby concatenating the two data portions. When the drive again encounters the affected data, the controller provides the contents of the buffer memory to a requestor in response to a request for the block of data. |
