Create a file "public-yum-el5.repo" in the directory /etc/yum.repos.d
[vm3_latest]
name=Oracle Linux $releasever Latest ($basearch)
baseurl=http://public-yum.oracle.com/repo/OracleVM/OVM3/latest/x86_64/
gpgkey=http://public-yum.oracle.com/RPM-GPG-KEY-oracle-el5
gpgcheck=1
enabled=1
and run “yum update”
This will upgrade Oracle VM to latest version
