You can upgrade a vCenter Single Sign-On instance that is deployed on a separate virtual machine or physical server from vCenter Server to an externally deployed Platform Services Controller 6.0 while leaving the vCenter Server instances that are using it at version 5.5.

If you upgrade an externally deployed vCenter Single Sign-On instance to an externally deployed Platform Services Controller 6.0, the vCenter Server 5.5 instances that were using the vCenter Single Sign-On instance are not affected. The vCenter Server 5.5 instances continue to operate with the upgraded Platform Services Controller as they did before the upgrade without any problems or required reconfiguration. vCenter Server 5.5 instances continue to be visible to vSphere Web Client 5.5, though vCenter Server 6.0 instances are not visible to vSphere Web Client 5.5.

Mixed-version transitional behavior is the same for vCenter Single Sign-On instances deployed in vCenter Server 5.5 for Windows environments and in vCenter Server Appliance environments.

Figure 1. Mixed-Version Environment


Mixed version vCenter Server 5.5 and 6.0 instances with an external Platform Services Controller 6.0


Note:

Mixed-version environments are not supported for production. They are recommended only during the period when an environment is in transition between vCenter Server versions.

If you upgrade an external vCenter Single Sign-On and at least one instance of vCenter Server to version 6.0 while leaving other instances of vCenter Server at version 5.5, expect these results:

  • Linked Mode no longer functions.

  • vCenter Server 5.5 instances continue to operate with the upgraded Platform Services Controller as they did before the upgrade without any problems or required reconfiguration.

  • In a vCenter Server mixed-version 5.5 and 6.0 environment, a vSphere Web Client 6.0 instance shows vCenter Server 5.5 instances.

  • vSphere Web Client 5.5 shows vCenter Server instances only, not 6.0 instances.

If you upgrade all vCenter Server 5.5 instances to version 6.0 and the distributed vCenter Single Sign-On instance to an external Platform Services Controller, none of the vCenter Server instances are affected. They continue operating with the Platform Services Controller as they did before the upgrade without any problems or required action.

The only action required for a mixed-version 5.5 and 6.0 environment after upgrade is a restart of any legacy vSphere Web Client instances if they will be used to view vCenter Server 5.5 instances that are not yet upgraded.

Figure 2. Example Deployment Before Upgrade Begins


Example deployment with three vCenter Server 5.5 instances and two external vCenter Single Sign-On 5.5 instances before upgrade begins


For example, a deployment with three vCenter Server 5.5 instances and two external vCenter Single Sign-On instances must be upgraded one instance at a time to version 6.0.

Figure 3. Example Deployment in Transition at Step 1


Example deployment with three vCenter Server 5.5 instances, one external vCenter Single Sign-On 5.5 instance, and one external Platform Services Controller 6.0 instance

Upgrading the first external vCenter Single Sign-On instance to an external Platform Services Controllerhas no impact on the vCenter Server 5.5 instances except that Linked Mode no longer functions.

Figure 4. Example Deployment in Transition at Step 2


Example deployment with three vCenter Server 5.5 instances and two external Platform Services Controller 6.0 instances


Upgrading the second external vCenter Single Sign-On instance to an external Platform Services Controllerhas no impact on the behavior of the vCenter Server 5.5 instances.

Figure 5. Example Deployment in Transition at Step 3


Example deployment with one vCenter Server 6.0 instance, two vCenter Server 5.5 instances, and two external Platform Service Controller 6.0 instances


After upgrading the first vCenter Server instance to 6.0, changes occur in the connectivity between the vCenter Server instances.

  • The two remaining vSphere Web Client 5.5 instances can no longer view the newly upgraded vCenter Server 6.0 instance after it joins the Platform Services Controller instance.

  • The vSphere Web Client 5.5 instances can still view the vCenter Server 5.5 instances after the vSphere Web Client 5.5 instances are restarted.

  • The vSphere Web Client 6.0 instance that is part of the newly upgraded vCenter Server 6.0 instance can view the vCenter Server 5.5 and vCenter Server 6.0 instance.

Figure 6. Example Deployment in Transition at Step 4


Example deployment with two vCenter Server 6.0 instances, one vCenter Server 5.5 instance, and two external Platform Service Controller 6.0 instances


After upgrading the second vCenter Server instance to 6.0, further changes occur in the connectivity between the vCenter Server instances:

  • Linked Mode functionality is replaced by Enhanced Linked Mode functionality between the newly upgraded vCenter Server 6.0 instances after they are joined to the Platform Services Controller.

  • The remaining vSphere Web Client 5.5 instance can no longer view the vCenter Server 6.0 instances.

  • The vSphere Web Client 5.5 instance can still view the vCenter Server 5.5 instance after the vSphere Web Client 5.5 instance is restarted.

  • The vSphere Web Client 6.0 instances that are part of the newly upgraded vCenter Server 6.0 instances can view the vCenter Server 5.5 and vCenter Server 6.0 instances.

Figure 7. Example Deployment in Transition at Step 5 with Upgrade Complete


Example deployment with three vCenter Server 5.5 instances and two external Platform Services Controller 6.0 instances


After upgrading the third and final vCenter Server instance to 6.0, all the vCenter Server instances are connected with vCenter Server 6.0 functionality.

  • Linked Mode functionality is replaced by Enhanced Linked Mode functionality between all the vCenter Server 6.0 instances after they are joined to the Platform Services Controller.

  • The vSphere Web Client 6.0 instances can view all the vCenter Server 6.0 instances.