Planning Use Case: Decommission a Cluster or Datacenter

Document created by Michael Scott Expert on Oct 16, 2015Last modified by fran.schwarzmann on Aug 15, 2016
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Decommission a Cluster or Datacenter

Assume you want to decommission one datacenter, and move all its workload to a different datacenter. Does the target datacenter have enough physical resources to support the workload you plan to move? Where should that workload be placed? How can you calculate the effect such a change would have on your overall infrastructure?


You can set up a scenario to simulate this change for you, and show the most desirable workload distribution in the target datacenter. In addition, the scenario can generate a PDF report that describes the final environment and lists the actions that the plan took to achieve that result. You can run such a scenario to simulate decommissioning an entire datacenter, or a given cluster.


To calculate this information, create a plan that:

  • Limits the plan scope to two datacenters (or clusters) — the one you will decommission, and the one that will take on the extra workload
  • Eliminates all the hardware from the decommissioned datacenter
  • Calculates workload placement across datacenter (or cluster) boundaries
  • Does not provision new hardware to support the workload

When you run it, the plan will move the workload from the closed down datacenter onto the one that is still in service. If that datacenter has enough resources to support the workload, the plan lists all the actions you can take to achieve the desired results. If the datacenter doesn’t have enough resources to support the workload, the plan lists the VMs that could not be placed.The following steps show how to create and run such a plan:

  1. Start a new plan.

     This clears the plan so you can specify a new plan based on your current environment.

     For this plan, you will create a scenario without using the Plan Wizard.     

     To start a new plan, click to edit the scope — editing scope always starts a new plan.image

2.  Set the plan scope

     For this use case you will close down one datacenter and move its workload to another one that will remain in service. To set up this scenario, set the plan’s      scope to include just these two datacenters.


3.  Decommission the datacenter.  Modify the plan’s supply (click image).imageimage

NOTE: This use case can serve to decommission datacenters or clusters. To be thorough for decommissioning a datacenter, you can repeat this step for storage to remove the datacenter’s datastores. However, when decommissioning a cluster, you should not remove the cluster’s datastores — it’s likely that datastores are shared across clusters.

4.  Disable hardware provisioning.

     To make sure the plan places the stranded workload on just the existing hardware in your remaining datacenter, you must disable hardware provisioning.

     Edit the Advanced Settings (click image) to disable hardware provisioning.image

5.  Run the plan.To enable moving workload across datacenters and clusters, be sure to enable Ignore constraints before you run the plan (image). In this mode, the plan can move your stranded workload to the in-service datacenter.


After a successful run, you can review the results in the Plan view. The results will tell you whether the workload from the decommisioned datacenter can run on the datacenter that is still in service. For information about this Results view, see One-time Plan Results.


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Go To: The Plan View Glossary