Pre-Installion tasks for pretty much database versions

 Here are some pre-installation tasks before installing Oracle Database software, some of the steps or statement may vary from versions to versions.

• First of all create groups like oinstall, dba. (must 2 groups) Other groups like oper is optional and asmadmin, asmdba, asmoper are related to ASM / Grid Installation. Create user oracle who will be responsible for installation.

 [root@localhost /]# groupadd -g 501 oinstall  
 [root@localhost /]# groupadd -g 502 dba  
 [root@localhost /]# groupadd -g 503 oper  
 [root@localhost /]# groupadd -g 504 asmadmin  
 [root@localhost /]# groupadd -g 505 asmdba  
 [root@localhost /]# groupadd -g 506 asmoper  
 [root@localhost ~]# useradd -u 501 -g oinstall -G dba,oper,asmadmin,asmdba,asmoper oracle  

• Now login as oracle user and then edit .bash_profile and add following code to that file:

 [root@localhost ~]# su – oracle  
 [oracle@localhost ~]$ cat .bash_profile  
 # .bash_profile  
 # Get the aliases and functions  
 if [ -f ~/.bashrc ]; then  
     . ~/.bashrc  
 fi  
 # User specific environment and startup programs  
 PATH=$PATH:$HOME/bin  export PATH  
 # Oracle Settings  
 TMP=/tmp; export TMP  
 TMPDIR=$TMP; export TMPDIR  
 ORACLE_HOSTNAME=localhost.localdomain; export ORACLE_HOSTNAME  
 # ORACLE_UNQNAME=DB11G; export ORACLE_UNQNAME  
 ORACLE_BASE=/u01/app/oracle; export ORACLE_BASE  
 ORACLE_HOME=$ORACLE_BASE/product/11.2.0/db_1; export ORACLE_HOME  
 # ORACLE_SID=DB11G; export ORACLE_SID  
 PATH=/usr/sbin:$PATH; export PATH  
 PATH=$ORACLE_HOME/bin:$GRID_HOME/bin:$PATH; export PATH  
 LD_LIBRARY_PATH=$ORACLE_HOME/lib:/lib:/usr/lib; export LD_LIBRARY_PATH  
 CLASSPATH=$ORACLE_HOME/jlib:$ORACLE_HOME/rdbms/jlib; export CLASSPATH  

• Now create the necessary directories and assign them with proper group and user. (skip if already created.)

 [root@localhost /]# mkdir -p /u01/app/oracle/product/11.2.0/db_1  
 [root@localhost /]# ls /u01/app/oracle/product/11.2.0/  
 db_1  
 [root@localhost /]# chown -R oracle:oinstall /u01/  
 [root@localhost /]# chmod -R 775 /u01/