48.View the Exhibit to examine the error obtained during the I/O calibration process. There are no data files on raw devices. What is the reason for this error?
A. The DISK_ASYNCH_IO parameter is set to TRUE.
B. The FILESYSTEMIO_OPTIONS parameter is set to NONE.
C. Another session runs the I/O calibration process concurrently.
D. The pending area has not been created before running the I/O calibration process.
Answer: B
您可以使用FILESYSTEMIO_OPTIONS初始化参数来启用或禁用异步I/O或直接对文件系统文件执行I/O。此参数是特定于平台的,并且具有最适合特定平台的默认值。
FILESYTEMIO_OPTIONS can be set to one of the following values:
ASYNCH: enable asynchronous I/O on file system files, which has no timing requirement for transmission.
DIRECTIO: enable direct I/O on file system files, which bypasses the buffer cache.
SETALL: enable both asynchronous and direct I/O on file system files.
NONE: disable both asynchronous and direct I/O on file system files.