Q: Is the VM still running, i.e. can you ssh to the VM?
Q: Find the server where the VM is running, and restart the ovs-agent, i.e. "service ovs-agent restart". Did this help, or is the agent crashed, any zombies?
Possible root cause: These type of errors are typically ovs-agent bugs. First update oracle vm manager to the 3.2.4 release, not 3.2.6. Next update the dom0s to 3.2.4, not 3.2.6. You may need to setup a ULN 3.2.4 yum repo to update the dom0s. As you can see in these forms, 3.2.6 is may not ready for prime time, stick with 3.2.4, is stable.