Enabling Asynchronous I/O And Direct I/O Support; Relinking Oracle9I R2 To Enable Asynchronous I/O Support - Red Hat ENTERPRISE LINUX 5.1 - LINUX ORACLE Tuning Manual

Oracle 9i and 10g tuning guide

Table of Contents

Chapter 12.

Enabling Asynchronous I/O and Direct

I/O Support

Asynchronous I/O permits Oracle to continue processing after issuing I/Os requests which leads to

higher I/O performance. Red Hat Enterprise Linux also allows Oracle to issue multiple simultaneous

I/O requests with a single system call. This reduces context switch overhead and allows the kernel to

optimize disk activity.

To enable asynchronous I/O in Oracle Database, it is necessary to relink Oracle 9i and 10g Release 1.

Note

10g Release 2 is shipped with asynchronous I/O support enabled and does not need to be

relinked. But you may have to apply a patch, see below.

12.1. Relinking Oracle9i R2 to Enable Asynchronous I/O

Support

Note

Oracle 9iR2 on Red Hat Enterprise Linux 3, 4 and 5 the 9.2.0.4 patchset or higher

needs to be installed together with another patch for asynchronous I/O, see Metalink

Note:279069.1.

To relink Oracle9i R2 for asynchronous I/O, execute the following commands:

# shutdown Oracle

SQL> shutdown

su - oracle

$ cd $ORACLE_HOME/rdbms/lib

$ make -f ins_rdbms.mk async_on

$ make -f ins_rdbms.mk ioracle

# The last step creates a new "oracle" executable "$ORACLE_HOME/bin/oracle".

# It backs up the old oracle executable to $ORACLE_HOME/bin/oracleO,

# it sets the correct privileges for the new Oracle executable "oracle",

# and moves the new executable "oracle" into the $ORACLE_HOME/bin directory.