OVF ExtraConfig elements provide a flexible way of including key=value pairs in the configuration of a virtual machine. The keys and values are interpreted by the system when the virtual machine is deployed, and can be used to specify a variety of virtual machine properties.

The VMware Cloud Director API supports several ExtraConfig key=value pairs that you can use to configure virtual machines for specific types of workloads. You can use OVFtool to create an OVF package that includes virtual machines with these ExtraConfig values.

Permission to upload or download a Vm that includes any of these keys requires one or more of the following rights.
Table 1. ExtraConfig Keys, Values, and Required Rights
Key Values Required Right Description
any key any value vApp: Preserve All ExtraConfig Elements During OVF Import and Export A user with this right can upload or download an OVF package that contains an unlimited set of ExtraConfig key=value pairs. The set includes, but is not limited to, the pairs listed in this table.
any key that is a value of the vapp.allowed.extra.config system configuration property any value vApp: Allow Matching Extra Config A user with this right can upload or download an OVF package that contains any of the ExtraConfig key=value pairs in which the key is a value of the vapp.allowed.extra.config system configuration property. See VMware Knowledge Base article https://kb.vmware.com/kb/2148573.
sched.cpu.latencySensitivity high, normal (default) vApp: Preserve Latency ExtraConfig Elements During OVF Import and Export Set to high for virtual machines running latency-sensitive workloads.
ethernetn.coalescingScheme

(where n is the number of the virtual NIC in the range 0-9)

enabled, disabled (default) vApp: Preserve Ethernet-Coalescing ExtraConfig Elements During OVF Import and Export Set to enabled and specify the virtual NICs that must disable interrupt coalescing.
numa.nodeAffinity n, ..., where n is a NUMA node number on the host. vApp: Preserve NUMA Node Affinity ExtraConfig Elements During OVF Import and Export Constrains the set of NUMA nodes on which a virtual machine's virtual CPU and memory can be scheduled.
sched.mem.lpage.enable1GPage true, false (default) vApp: Allow Latency Extra Config
Set the key to true for virtual machines with 1 GB page size.
Important: Virtual machines with 1 GB page size are supported only for virtual datacenters with 100% memory resources guaranteed.
A user with vApp: Allow Latency Extra Config right can:
  • import an OVF with 1 GB page size into VMware Cloud Director as a vApp or vApp template.
  • download a vApp or vApp template with 1 GB page size as an OVF or OVA.
  • instantiate from a vApp template with 1 GB page size
  • import and auto import a virtual machine with 1 GB page size from vCenter into VMware Cloud Director.
For detailed information about the effects of these settings, see Best Practices for Performance Tuning of Telco and NFV Workloads in vSphere ( http://www.vmware.com/files/pdf/techpaper/vmware-tuning-telco-nfv-workloads-vsphere.pdf). For information about using the VMware Cloud Director API to add rights to a role, see Create a Role in Your Organization.

Applying ExtraConfig Values to a Virtual Machine

This example shows how to use OVFtool to create an OVF package that contains a VirtualHardwareSection with an ExtraConfig setting. 
<?xml version="1.0" encoding="UTF-8"?>
<Vm ...>
   ...
   <ovf:VirtualHardwareSection
      xmlns:vcloud="http://www.vmware.com/vcloud/v1.5"
      ovf:transport="">
      <ovf:Info>Virtual hardware requirements</ovf:Info>
      <vmw:ExtraConfig
         ovf:required="false"
         vmw:key="sched.cpu.latencySensitivity"
         vmw:value="high" />
      ...
   </ovf:VirtualHardwareSection>
   ...
</Vm>
You can log in to VMware Cloud Director as a user whose role includes the right vApp: Preserve Latency ExtraConfig Elements During OVF Import and Export and upload the OVF package that you created.