Workload Balance offers you the potential to fully automate a significant portion of your cluster workload rebalancing tasks. The tasks to accomplish workload automation are as follows:

  1. Set the policies that define demand limits for cluster CPU and memory. See Workload Policy Settings.

  2. Configure the Workload Automation Details to complement the policies. See Workload Automation Details.

  3. Configure the two Workload Balance alerts to be triggered when cluster CPU/memory limits are breached, and configure them as automated. When the alerts are automated, the recommended actions calculated by Workload Balance are executed automatically. See Configuring Workload Balance Alerts

Prerequisites

Workload Balance acts on objects associated with the VMware vSphere Solution that connects vRealize Operations Manager to one or more vCenter Server instances. The virtual objects in this environment include a vCenter Server, data centers and custom data centers, cluster compute and storage resources, host systems, and virtual machines. Specific requirements:

  • A vCenter Adapter configured with the actions enabled for each vCenter Server instance.

  • A vCenter Server instance with at least two datastore clusters with sDRS enabled and fully automated.

  • Any non-datastore clusters must have DRS enabled and fully automated

  • Storage vMotion must be set to ON at Workload Automation Details. The default is On.

  • You must have permission to access all objects in the environment.

Design Considerations

The following rules constrain the possible computer and storage resource moves that can be performed.

Note:

When vRealize Operations Manager recommends that you rebalance clusters in a data center, the system does not guarantee a rebalance action will occur. vRealize Operations Manager analytics can determine that a rebalance is desirable and can create a rebalancing plan. However, the system cannot automatically identify all of the architectural constraints that may be present. Such constraints may prevent a rebalance action, or cause an action in progress to fail.

  • Moving compute and storage resources is allowed only within, not across data centers or custom data centers.

  • Storage resources cannot be moved across non-datastore clusters. Storage can move only across datastore clusters that have sDRS fully automated.

  • Compute-resource-only moves are permitted via shared storage.

  • Virtual machines defined with affinity rules and/or anti-affinity rules are not to be moved.

  • Virtual machines cannot be moved when residing on a local datastore, unless a storage swap exists on the local datastore.

  • Virtual machines cannot be moved if they have data residing across multiple datastore clusters. Compute-only moves with similar shared storage are not permitted.

  • A virtual machine cannot have data that resides across different storage types. This means, for example, that if a virtual machine that has a vmdk on a datastore and a second vmdk on a datastore cluster, the virtual machine does not move, even when the datastore is shared with the destination or has swap on it.

  • A virtual machine can use RDM so long as the destination datastore cluster can access the RDM LUN.

  • A virtual machine can implement vmdks on multiple datastores inside a single datastore cluster.

  • Virtual machines cannot be placed inside clusters managed by vRealize Automation.

  • Workload Balance may recommend moving virtual machines that are protected via vSphere Replication or Array Based Replication. It is recommended to ensure that all the clusters within a selected Datacenter or Custom Datacenter have replication available. You can set up DRS Affinity Rules on virtual machines that you do not want moving across clusters.