Configuring a Global Placement Strategy

Configuring the default global placement strategy for new services, involves the following tasks:

Prioritizing Intelligent Placement criteria

When Commander predicts and selects the best deployment destination for a new service request, it first filters out invalid destinations. Each valid destination is then rated, based on the following criteria:

  • Quota: How much quota is available on this destination for the requester and the requester's organization, when per-destination quota is configured?
  • Cost: How much will this service cost on this destination? To learn how Commander calculates the cost of a service, see Service Costs
  • Placement attributes: Does this destination provide the capabilities preferred for this service? To learn how to create and apply placement attributes, see Configuring Placement Attributes.

Access through:

Configuration > Self-Service

Available to:

Commander role of Superuser

To prioritize Intelligent Placement criteria:

  1. Click the Placement tab.
  2. On the Placement page, select Placement Strategy.
  3. In the Placement Priority section, use the up and down arrows to re-order the placement priorities.
  4. Click Save to apply your changes.

Configuring datastore placement preferences

Datastore Placement settings apply to vCenter and SCVMM cloud accounts.

To ensure that new and expanded disks are placed on a datastore with sufficient storage space, Commander reserves storage as soon as the deployment of a new service request or the fulfillment of a change request starts. This is true for manual deployment and fulfillment, automated deployment and fulfillment, scheduled fulfillment, vCenter migration, and the manual Reconfigure Resources command.

Once deployment or fulfillment has succeeded (or failed), the storage reservation is released.

Access through:

Configuration > Self-Service

Available to:

Commander role of Superuser

To configure the datastore placement settings:

  1. Click the Placement tab.
  2. On the Placement page, select Placement Strategy.
  3. In the Datastore Placement section, enter a percentage value in the Prevent deployment when datastore is more than <n> % full drop-down list to set the threshold for datastore usage.

    This threshold prevents over-utilization of datastores when a VM is being deployed because a deployment will fail only if all datastores assigned to the target storage tier would exceed this threshold. If you have configured email notification for all requests, emails are sent when all datastores assigned to a storage tier used in a deployment destination have exceeded this threshold. The default is 80%, meaning that deployment fails when it would cause the target datastore to be more than 80% full. A value of 0% removes the threshold.

    Tip: Schedule a search for datastores that are approaching the configured threshold. Go to Tools > Search and select Datastores. Run the public search "Datastores with less than 20% free space". Click View Query, and adjust the parameters as required. Run the search and click Schedule. See Running and Scheduling Saved Searches.

  4. From the Datastore Filling Strategy drop-down list, select one of the following options:
    • Choose datastore with the most free space — Commander deploys to the datastore with the most free space, up to the configured threshold. This is the default setting.
    • Leave largest block of free space available — Commander tries to fill up an available datastore before moving on to the next datastore. You may use this setting if you need to change the default behavior in order to leave large amounts of free space available for large VMs, under Datastore Filling Strategy.

    With either option, the datastore must match the storage tier requested for disks, and all the VM's disks with the same tier must fit into the datastore, without exceeding the threshold.

  5. From the Calculate disk size for placement using drop-down list, select one of the following options:
    • Actual space that deployed service will consume — Commander uses the current "used space" of the source template when calculating disk size for a thin-provisioned disk. For linked clones, Commander uses a disk size of 0. This setting allows you to provision VMs that significantly over-commit the datastore, so you should select this setting when you know that VMs are unlikely to grow to their full size. This is the default setting.
    • Full size of all configured disks — This setting allows placement to accommodate possible VM growth that may fill the disk. You may want to use this setting if you want Commander to ignore the fact that the disk will be thin-provisioned, or that the VM will be a linked clone.
  6. Click Save to apply your changes.