diff --git a/doc/config-reference/compute/section_hypervisor_vmware.xml b/doc/config-reference/compute/section_hypervisor_vmware.xml
index fd05499ebb..0cdf3b8bb4 100644
--- a/doc/config-reference/compute/section_hypervisor_vmware.xml
+++ b/doc/config-reference/compute/section_hypervisor_vmware.xml
@@ -176,6 +176,14 @@
           not currently supported.
         </para>
       </listitem>
+      <listitem>
+        <para>
+          To use multiple vCenter installations with OpenStack, each vCenter
+          must be assigned to a separate availability zone. This is required
+          as the OpenStack Block Storage VMDK driver does not currently work
+          across multiple vCenter installations.
+        </para>
+      </listitem>
     </orderedlist>
   </section>
   <section xml:id="VMWareVCDriver_details">