If the virtual machine is derived from an Oracle VM template that does have the Oracle VM Guest Additions installed, you may need to update the packages in order for the Oracle VM Guest Additions to function correctly. Using the Oracle Unbreakable Linux Network (ULN) (http://linux.oracle.com) YUM repository you can run the following command to update the packages:

# yum update ovmd libovmapi xenstoreprovider \
  ovm-template-config \
  ovm-template-config-authentication \
  ovm-template-config-datetime \
  ovm-template-config-firewall \
  ovm-template-config-network \
  ovm-template-config-selinux \
  ovm-template-config-ssh \
  ovm-template-config-system \
  ovm-template-config-user

If you are using a kernel version lower than UEK 2.6.39-300, and you want to continue to use the current kernel, you must also run the following command to update the ovmapi.ko module:

# yum update kmod-ovmapi-uek

Alternatively, you can update your kernel to the latest UEK version by running the following command:

# yum update kernel-uek

If you are using Oracle Linux 5, you need to enable ol5_UEK_latest within /etc/yum.repos.d/ULN-Base.repo, before you attempt to update your kernel version. For example, the file should contain the following lines:

[ol5_UEK_latest]
name=Latest Unbreakable Enterprise Kernel for Oracle Linux $releasever ($basearch)
baseurl=http://public-yum.oracle.com/repo/OracleLinux/OL5/UEK/latest/$basearch/
gpgkey=http://public-yum.oracle.com/RPM-GPG-KEY-oracle-el5
gpgcheck=1
enabled=1