Examine these details from the sysctl.conf file and from the proc file system:
[root@FAROUT fs]# grep aio-max-nr /etc/sysctl.conf
# oracle-rdbms-server-11gR2-preinstall setting for fs.aio-mx-nr is 1048576
fs.aio-max-nr = 1048576
[root@FAROUT fs] # cat /proc/sys/fs/aio-max-nr
1048576
[root@FAROUT fs] # rpm –q libaio
Libaio-0.0.107-10.e16.x86_64
Libaio-0.3.107-10.e76.i686
Which statement is true about the setting created by oracle-rdbms-server-11gR2-preinstall?
A.
It allows a process to request an I/O without waiting for reply.
B.
It allows two or more processes to request I/O simultaneously while running on different CPUs.
C.
It allows a process to request a single I/O without awaiting for a reply. However, if a second I/O
is requested, then the process must wait.
D.
It allows two or more processes to request I/Os and then to both be notified when both of them
complete.
Explanation:
B
A
The idea behind AIO is to allow a process to initiate several I/O operations without having to block or wait for any to complete. At some later time, or after being notified of I/O completion, the process can retrieve the results of the I/O.
The /proc/sys/fs/aio-max-nr file is the maximum number of allowable concurrent requests. This is related to asynchronous I/O usage on your system.
aio-max-nr 1048576
Note: This value limits concurrent outstanding requests and should be set to avoid I/O subsystem failures.
/proc/sys/fs/aio-max-nr
aio-nr & aio-max-nr:
aio-nr is the running total of the number of events specified on the
io_setup system call for all currently active aio contexts. If aio-nr
reaches aio-max-nr then io_setup will fail with EAGAIN. Note that
raising aio-max-nr does not result in the pre-allocation or re-sizing
of any kernel data structures.
So I would go for A
A