Oracle 10gR2 enables asynchronous IO under RHEL 5

Oracle 10gR2 enables asynchronous IO under RHEL 5

Record the steps for enabling asynchronous IO for Oracle 10gR2 under RHEL 5

Platform: RedHat Enterprise Linux 5 64bit, Oracle 10gR2 10.2.0.4 64bit

1. First install the following necessary rpm packages with the root user

# Rpm-Uvh libaio-0.3.106-3.2.x86_64.rpm

# Rpm-Uvh libaio-devel-0.3.106-3.2.x86_64.rpm

2. Supporting asynchronous I/O at the system level

Unlike setting asynchronous IO in RHEL 3 described in [Note 225751.1], you do not need to set aio-max-size, the file does not exist in the '/proc/sys/fs' path. Since 2.6 kernel, I/O size restrictions have been removed [Note 549075.1]. In addition, according to [Note 471846.1], Oracle recommends setting the aio-max-nr value to 1048576 or higher.

# Echo>/proc/sys/fs/aio-max-nr 1048576

To permanently modify this Kernel Parameter, add the following sentence to/etc/sysctl. conf:

Fs. aio-max-nr = 1048576
Make parameters take effect
#/Sbin/sysctl-p

3. Enable asynchronous I/O at the database level

First, modify the database parameters. Unlike [Note 225751.1] setting asynchronous IO in RHEL 3, Oracle10gR2 enables support for asynchronous IO by default and does not need to re-compile the database software. In the '$ ORACLE_HOME/rdbms/lib' path, there is no 'skgaioi. o' file. In some cases, Oracle cannot report IO behaviors or events to the operating system [Note 365416.1]. Therefore, you need to perform the following operations.

Change to oracle user

SQL> alter system set disk_asynch_io = TRUE scope = spfile;

SQL> alter system set filesystemio_options = asynch scope = spfile;

SQL> shutdown immediate

$ Cd $ ORACLE_HOME/rdbms/lib

$ Ln-s/usr/lib/libaio. so.1 skgaio. o

$ Make PL_ORALIBS =-laio-f ins_rdbms.mk async_on

SQL> startup

In Oracle10gR2, AIO is enabled by default. You can use ldd or nm to check whether oracle has enabled AIO support. If the output is enabled.

[Oraprod @ db01 ~] $/Usr/bin/ldd $ ORACLE_HOME/bin/oracle | grep libaio

Libaio. so.1 =>/usr/lib64/libaio. so.1 (0x00002aaaac4a9000)

[Oraprod @ db01 ~] $/Usr/bin/nm $ ORACLE_HOME/bin/oracle | grep io_getevent

W io_getevents @ LIBAIO_0.4

4. Check whether asynchronous I/O is in use

According to [Note 370579.1], you can view the slabinfo statistics to check whether AIO is running in the operating system. slab is a Linux memory distributor and the memory structure related to AIO has been allocated, the second and third columns of the kiocb values are used if they are not 0. Unlike kernel 2.4.x, kiobuf is not displayed because kiobuf has been removed from the kernel since kernel 2.5.43.

$ Cat/proc/slabinfo | grep kio

Kioctx 64 110 384 10 1: tunables 54 27 8: slabdata 11 11 0

Kiocb 13 315 256 15 1: tunables 120 60 8: slabdata 21 21 44

Oracle 11g installation manual on RedHat Linux 5.8 _ x64 Platform

Installing Oracle 12C in Linux-6-64

Install Oracle 11gR2 (x64) in CentOS 6.4)

Steps for installing Oracle 11gR2 in vmwarevm

Install Oracle 11g XE R2 In Debian