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.
Explanation:
9.1.1.2 FILESYSTEMIO_OPTIONS Initialization Parameter
You can use the FILESYSTEMIO_OPTIONS initialization parameter to enable or disable
asynchronous I/O or direct I/O on file system files. This parameter is platform-specific and
has a default value that is best for a particular platform.
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.
To enable asynch I/O, set two values in the init.ora file (or spfile) and recycle the instances:
disk_asynch_io = true
filesystemio_options = asynch
The first one is default; so you may not have to change it. The default of the second one is
NONE; so you will probably have to change it. After setting these values and recycling the
instance,
B is correct:
https://oracle-base.com/articles/misc/direct-and-asynchronous-io
Oracle can take advantage of direct I/O and asynchronous I/O on supported platforms using the FILESYSTEMIO_OPTIONS parameter, whose possible values are listed below.
ASYNCH – Enabled asynchronous I/O where possible.
DIRECTIO- Enabled direct I/O where possible.
SETALL- Enabled both direct I/O and asynchronous I/O where possible.
NONE – Disabled both direct I/O and asynchronous I/O.