Link repo download CentOS

http://mirror-fpt-telecom.fpt.net/centos/5.6/isos/i386/
http://mirror-fpt-telecom.fpt.net/centos/5.5/isos/i386/
http://mirror-fpt-telecom.fpt.net/centos/6.0/isos/i386/

x86_64:
http://vault.centos.org/5.6/os/x86_64/CentOS/

Thao tác với Oracle

cd ORACLE_HOME
./sqlplus /nolog

lsnrctl status
hoặc lsnrctr