This article will assist you to set permanently the kernel parameters on RedHat Advanced Server and on United Linux
Oracle uses UNIX resources such as shared memory, swap space, and semaphores extensively for interprocess communication. If your kernel parameter settings
are insufficient for Oracle, you will experience problems during installation and/or instance startup.
To modify kernel parameters a common way is to change /proc file system:
1. Log in as root user.
2. Change to the /proc/sys/kernel directory.
3. echo <desired list of values> > <group of parameters>
But this update is not permanent and after system reboot, your kernel parameters’s values will be the same as before.
A way to set kernel parameter modifications permanently, on Linux, is to includethem in a shell script. This could be run as root user, or in an automatic way at startup process (this is valid for RedHat Advanced Server and UnitedLinux)
- Create file /etc/init.d/set_kernel_parameters
#!/bin/sh
#
#
echo -n $”Start Setting kernel parameters on ”
echo 100 1024 100 100 > /proc/sys/kernel/sem
echo 2147483648 > /proc/sys/kernel/shmmax
echo 4096 > /proc/sys/kernel/shmmni
echo 2097152 > /proc/sys/kernel/shmall
echo 65536 > /proc/sys/fs/file-max
ulimit -n 65536 >/dev/null 2>&1
echo 1024 65000 > /proc/sys/net/ipv4/ip_local_port_range
ulimit -u 16384 >/dev/null 2>&1
echo -n $”End Setting kernel parameters on ”
echo
- grant execute rights on this file
$ chmod 755 /etc/init.d/set_kernel_parameters
- create symbolic link to run at startup
$ ln -s /etc/init.d/set_kernel_parameters /etc/rc.d/rc5.d/S55kernel
$ ln -s /etc/init.d/set_kernel_parameters /etc/rc.d/rc3.d/S55kernel
- make the kernel parameters active by running as root
$ /etc/init.d/set_kernel_parameters
RedHat Linux Advanced Server
——————————————
Another way to setup permanently kernel parameter values on Red Hat Advanced Server is to use ‘/etc/sysctl.conf’ file.
Every time the system boots, the ‘/etc/rc.d/rc.sysinit’ script is executed by init process. This shell script contains a call to sysctl command and
reads the values from /etc/sysctl.conf file as the ones to be set Therefore, any values added to /etc/sysctl.conf will take effect after the system boot.
sysctl.conf is a simple file containing sysctl values to be read in and set by sysctl (see man 8 sysctl).
The syntax is simply as follows:
# comment
; comment
token = value
Note that blank lines are ignored, and whitespace before and after a token
or value is ignored, although a value can contain whitespace within. Lines
which begin with a # or ; are considered remarks / comments and ignored.
EXAMPLE:
# sysctl.conf sample
#
net.ipv4.ip_forward = 0
net.ipv4.conf.default.rp_filter = 1
kernel.sysrq = 1
kernel.sem = 100 1024 100 100 #This sets SEMMSL, SEMMNS, SEMOPM, SEMMNI
kernel.shmmax = 2147483648
kernel.shmmni = 100
net.ipv4.ip_local_port_range = 1024 65000
fs.file-max = 65536
The sysctl command is used to view, set, and automated kernel settings
in the /proc/sys/ directory. To get a quick overview of all settings
configurable in the /proc/sys/ directory, type the sysctl -a command as
root. This will create a large, comprehensive list.
United Linux
——————–
On United Linux another way to set kernel parameter modifications permanently
is to use the ‘/etc/init.d/boot.local’ file.
You can put in that file the commands setting the kernel parameters.
At the boot time ‘boot.local’ is started and the these setting processed
EXAMPLE:
#! /bin/sh
#
# Copyright (c) 2002 SuSE Linux AG Nuernberg, Germany. All rights reserved.
#
# Author: Werner Fink <werner@suse.de>, 1996
# Burchard Steinbild <feedback@suse.de>, 1996
#
# /etc/init.d/boot.local
#
# script with local commands to be executed from init on system startup
#
# Here you should add things, that should happen directly after booting
# before we’re going to the first run level.
#
echo -n $”Start Setting kernel parameters on ”
echo 100 1024 100 100 > /proc/sys/kernel/sem
echo 2147483648 > /proc/sys/kernel/shmmax
echo 4096 > /proc/sys/kernel/shmmni
echo 2097152 > /proc/sys/kernel/shmall
echo 65536 > /proc/sys/fs/file-max
ulimit -n 65536 >/dev/null 2>&1
echo 1024 65000 > /proc/sys/net/ipv4/ip_local_port_range
ulimit -u 16384 >/dev/null 2>&1
echo -n $”End Setting kernel parameters on ”
echo
Again on United Linux (with orarun-1.8-5.i586.rpm a part of SP1)
you can use ‘/etc/sysconfig/oracle’ file to set kernel parameter
modifications permanently.
EXAMPLE:
SET_ORACLE_KERNEL_PARAMETERS=”yes”
SHMMAX=3294967296
SHMMNI=4096
SHMALL=2097152
SEMMSL=1250
SEMMNS=32000
SEMOPM=100
SEMMNI=256
IP_LOCAL_PORT_RANGE=”1024 65000″
FILE_MAX_KERNEL=131072
FILE_MAX_SHELL=65536
PROCESSES_MAX_SHELL=16384
RELATED DOCUMENTS
——————————-
- Linux Man Page for sysctl.conf (5)
-Default Kernel Parameters for Linux Intel for 9.X Database
-Default Kernel Parameters for Linux Intel for 8.1.X Database
-Where To Find Linux Kernel Parameters
-Linux: How to Check Current Shared Memory, Semaphore Values
