Oracle 10g Pre-installation steps for RHEL 5

Following are the steps required to configure Linux for Oracle Database 10g Release 2.

Verifying System Requirements

To verify that your system meets the minimum requirements for an Oracle Database 10g Release 2 database, log in as root and run the commands below.
To check the amount of RAM and swap space available, run this:
grep MemTotal /proc/meminfo

grep SwapTotal /proc/meminfo

Ex:

1. grep MemTotal /proc/meminfo
   MemTotal: 1034680 kB
2. grep SwapTotal /proc/meminfo
   SwapTotal: 1534196 kB

The minimum RAM required is 8GB, and the minimum required swap space is 10 GB. Allocating the Swap space will be based on the DBA team requirement, but the minimum space should be 10 GB.

Memory depends upon the application we are running. For example ,iHotlier database will be having more memory compared to Databridge.

Adding swap space
This option of adding swap space is required only if the server is not configured with the required amount of swap space at the time of installation.
Swapon and SwapOff are two command provided with Linux to enable/disable devices and files for paging and swapping.

1)Create Swap File using DD command
dd if=/dev/zero of=/extraswap bs=1M count=12048
2)Setup Linux swap area using MKSWAP command
# mkswap -c /extraswap
# swapon /extraswap
3)run "swapon -s" and view the addition made. or free -m" command to verify addition of your new swap space.
4) Make swap upgrade permanently available to OS through fstab file.
/extraswap        none     swap    sw        0 0 

Create the Oracle Groups and User Account

Next, create the Linux groups and user account that will be used to install and maintain the Oracle Database 10g Release 2 software.

Example:

Groupname	Group ID	Group ID
	Production	Pre-Prod
dba	1500	1601
oinstall	1501	1602
orasegp		1604
Username	User ID	User ID	Primary Group	Secondary Group	Default shell
	Production	Pre-Prod
oracle	1500	1600	Dba	oinstall	/bin/bash
gridagnt	1502	1605	Dba	oinstall	/bin/bash
gguser	1501		Dba	oinstall	/bin/bash
orase		1603	Dba	orasegp	/bin/bash

Set the password for all the user accounts.
Example for Pre-prod:

/usr/sbin/groupadd -g 1602  oinstall
/usr/sbin/groupadd -g 1601  dba
/usr/sbin/groupadd -g  1604    orasegp
/usr/sbin/useradd -m -u 1600 -g oinstall -G dba -s /bin/bash oracle
/usr/sbin/useradd -m -u 1605 -g oinstall -G dba -s /bin/bash gridagnt

# id oracle
uid=1600(oracle) gid=1602(oinstall) groups=1602(oinstall),1602(dba)

Following directories are being created in the root filesystem.

Production	Pre-prod
/u00  should be a partition of minimum size 15GB, but as a standard follow 30GB of local partition.  In production environment ./u01 is a separate partition mounted with external lun.  chown -R oracle:oinstall /u01  chown -R oracle:oinstall /u00  mkdir /u01  mkdir -p /u01/app/oracle  chown -R oracle:oinstall /u01/app/  chmod -R 775 /u01/app/	/data  is a separate partition mounted with external lun  ln -s /data /u01  chown -R oracle:oinstall /u01  chown -R oracle:oinstall /u00  mkdir -p /u01/app/oracle  chown -R oracle:oinstall /u01/app/oracle  chmod -R 775 /u01/app/oracle

Configuring Linux Kernel Parameters

The Linux kernel is a wonderful thing. Unlike most other *NIX systems, Linux allows modification of most kernel parameters while the system is up and running. There's no need to reboot the system after making kernel parameter changes. Oracle Database 10g Release 2 requires the kernel parameter settings shown below. The values given are minimums, so if your system uses a larger value, don't change it.

/etc/sysctl.conf
kernel.shmmax = 68719476736  (for pre-prod kernel.shmmax = 4180148224)
kernel.shmall = 4294967296
kernel.shmmni = 4096
kernel.sem = 250 32000 100 128
fs.file-max = 65536
net.ipv4.ip_local_port_range = 1024 65000
net.core.rmem_default=262144
net.core.wmem_default=262144
net.core.rmem_max=262144
net.core.wmem_max=262144

To change the modified Kernel parameters while runtime, execute the below command.
# sysctl  -p

Setting Shell Limits for the oracle User

Oracle recommends setting limits on the number of processes and open files each Linux account may use. To make these changes, cut and paste the following commands as root:

/etc/security/limits.conf
oracle soft nproc 2047
oracle hard nproc 16384
oracle soft nofile 1024
oracle hard nofile 65536

If necessary Stack and MaxLockMem, make these changes, cut and paste the following commands as root

/etc/security/limits.conf
oracle soft memlock 3145728
oracle hard memlock 4145728
oracle soft stack 32768
oracle hard stack 43768

/etc/pam.d/login
session required pam_limits.so

Follow the same steps for given below packages installation

yum update *
yum install binutils*
yum install lib-Xp*

yum install libXp*
yum install compat-*
yum install control-center-*
yum install gcc-*
yum install glibc-*
yum install libstdc++*
yum install make*
yum install sysstat*
yum install xorg-x11-libs*
yum install libaio*
yum install compat-libstdc++*
yum install xorg-x11-*
yum install openmotif*
yum instal glibc-devel*

# rpm -qa --queryformat "%{NAME}-%{VERSION}-%{RELEASE} (%{ARCH})\n" | grep glibc

Enable direct login to oracle and provide sudo to root access for DBA Group to complete the installation. Revoke root access and direct login for oracle from DBA once installation is completed *