Manage to install Oracle 11g on CentOS 4.4

using Only RAM 512M PC2100 266, end of installation the system running very slow probably due to the OUI screen. restart it after long wait.

don't set the ORACLE_BASE and ORACLE_HOME first else (becos I set wrong to be /u01/app as ORACLE_BASE) the oraInventory will be same directory level as the ORACLE_BASE
/u01/oraInventory is prompted instead of /u01/app/oraInventory

ORACLE_BASE should be /u01/app/oracle instead of /u01/app
ORACLE_HOME should be $ORACLE_BASE/product/11.1.0/db_1

this is ORACLE_BASE
mkdir -p /u01/app/oracle
chown -R oracle:oinstall /u01/app
chmod -R 775 /u01/app

edit /etc/hosts 10.0.0.12 localhost.localdomain localhost
install necessary packages and configure kernel settings
NMO setuid error: run root.sh in ORACLE_HOME to solve

put ORACLE_BASE, ORACLE_HOME, PATH, LD_LIBRARY_PATH, ORACLE_SID in .bash_profile. Need logout and login to take effect of the environment variable.

Mistake made: it should be db_1 not db_01

emctl start dbconsole
lsnrctl start
startup

all working properly afterwards.