Mount ISO image - CentOS

/opt/tmp
[root@centos tmp]# ls
V834394-01.iso
[root@centos tmp]# mkdir oraclelinux
[root@centos tmp]# mount -t iso9660 -o loop /opt/tmp/V834394-01.iso /opt/tmp/oraclelinux/
[root@centos tmp]# ls /opt/tmp/oraclelinux/
addons  EULA  images    LiveOS    RELEASE-NOTES-U3-en       repodata     RPM-GPG-KEY-oracle
EFI     GPL   isolinux  Packages  RELEASE-NOTES-U3-en.html  RPM-GPG-KEY  TRANS.TBL
[root@centos tmp]#

Flush DNS cache on CentOS

To flush the DNS on CentOS:

# service nscd restart

or 

# nscd -i hosts