OCP 1Z0 053 48

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 

http://docs.oracle.com/cd/E11882_01/server.112/e41573/iodesign.htm#PFGRF94383

8.3.1 Prerequisites for I/O Calibration

Before running I/O calibration, ensure that the following requirements are met:

• The user must be granted the SYSDBA privilege

• timed_statistics must be set to TRUE

• Asynchronous I/O must be enabled

  When using file systems, asynchronous I/O can be enabled by setting the FILESYSTEMIO_OPTIONS initialization parameter to SETALL.

• Ensure that asynchronous I/O is enabled for data files by running the following query:

  COL NAME FORMAT A50SELECT NAME,ASYNCH_IO FROM V$DATAFILE F,V$IOSTAT_FILE IWHERE  F.FILE#=I.FILE_NOAND    FILETYPE_NAME='Data File';

Additionally, only one calibration can be performed on a database instance at a time.

http://docs.oracle.com/cd/E11882_01/server.112/e41573/os.htm#PFGRF94412

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.