[Oracle DataBase Server 12.1 installation on Oracle Linux 6.7]: Configure system users and kernel parameters

Backup current config files:

# {
cp /etc/sysctl.conf /etc/sysctl.conf.bkp.$(date +%Y-%m-%d)
cp /etc/security/limits.conf /etc/security/limits.conf.bkp.$(date +%Y-%m-%d)
cp /etc/pam.d/login /etc/pam.d/login.bkp.$(date +%Y-%m-%d)
cp /etc/profile /etc/profile.bkp.$(date +%Y-%m-%d)
}

Creating users and groups

# groupadd -g 1000 oinstall
# groupadd -g 1001 dba
# groupadd -g 1002 oper

We create user oracle12 and add user to groups. Home folder for this user will be /home/oracle12

# useradd \
-g oinstall \
-G dba,oper \
-d /home/oracle12 \
-m oracle12

Setup password for user oracle12

# passwd oracle12

Change kernel parameters and back profile for user oracle12

1) Now we edit file /etc/sysctl.conf

I recommend to comment next parameters by 2 next command:

# sed -i.gres "s/kernel.shmmax/#kernel.shmmax/g" /etc/sysctl.conf
# sed -i.gres "s/kernel.shmall/#kernel.shmall/g" /etc/sysctl.conf

# vi /etc/sysctl.conf

kernel.shmmax = RAM (in bytes) / 2

Bytes of RAM you could get with command

# free -b
4152623104 / 2 = 2076311552

In the end of file /etc/sysctl.conf add:

############################################
#### Kernel Parameters for Oracle 12

kernel.sem = 250 32000 100 128
kernel.shmall = 2097152
kernel.shmmax = 2076311552
kernel.shmmni = 4096
fs.file-max = 6815744
fs.aio-max-nr = 1048576
net.ipv4.ip_local_port_range = 20000 65500
net.core.rmem_default = 262144
net.core.rmem_max = 4194304
net.core.wmem_default = 262144
net.core.wmem_max = 1048586
vm.min_free_kbytes = 23168

############################################

2) Edit file /etc/security/limits.conf

# vi /etc/security/limits.conf

Add next:

############################################
#### Settings required for Oracle 12

oracle12 soft nproc 2047
oracle12 hard nproc 16384
oracle12 soft nofile 1024
oracle12 hard nofile 65536
oracle12 soft stack 10240
oracle12 hard stack 32768

############################################

3) Edit file /etc/pam.d/login

# vi /etc/pam.d/login

Add next:

############################################
#### Settings required for Oracle 12

session required pam_limits.so
############################################

4) Edit file /etc/profile

# vi /etc/profile

Before

unset i
unset pathmunge

Add next:

###########################################
#### Shell limits for Oracle 12 user accounts

if [ $USER = "oracle12" ]; then
ulimit -u 16384 -n 65536
fi
############################################

Apply kernel parameter to working server you could by next command:

# sysctl -p

5) Edit file /home/oracle/.bash_profile

# su - oracle12

$  vi /home/oracle/.bash_profile

После

# User specific environment and startup programs

Add next

############################################
#### Oracle Parameters

umask 022

export ORACLE_BASE=/u01/oracle
export ORACLE_HOME=$ORACLE_BASE/database/12.1
export ORACLE_SID=orcl12
export ORACLE_UNQNAME=orcl12
export NLS_LANG=AMERICAN_AMERICA.AL32UTF8
export NLS_DATE_FORMAT="DD.MM.YYYY HH24:MI:SS"

export PATH=$PATH:$ORACLE_HOME/bin
export LD_LIBRARY_PATH=$ORACLE_HOME/lib

export NLS_DATE_FORMAT='dd/mm/yyyy hh24:mi:ss'

alias sqlplus='rlwrap sqlplus'
alias rman='rlwrap rman'

############################################

Apply new parameters to current session you could by next command:

$ source ~/.bash_profile