Managing placements for compute nodes

A placement is a group of compute nodes that share a distinctive feature. It can be a special license for software to run in virtual machines or an advanced CPU model. After you group nodes into a placement, you can assign an image to it. Then, all of the VMs created from this image will be placed on the nodes included in the placement. In this way, you can create placements to assign VMs that need a specific feature to the nodes that have it.

Limitations

• The same node can be included into several placements.
• A virtual machine that is assigned a placement can only be migrated between nodes in this placement. Similarly, a VM without a placement can only be migrated between nodes that are not in placements. When adding nodes to placements, make sure to provide migration options for various scenarios, including high availability and maintenance. Avoid situations when VMs cannot migrate because of limitations imposed by placements. In this case, a VM placement can be edited, as described in Managing virtual machines in placements.
• Self-service users can only use placements by creating VMs from images added to those placements. If all of the nodes are in placements, make sure that at least one image is added to a placement. Otherwise self-service users will not be able to create virtual machines.
• You can add to a placement only images that are shared between all projects.
• You cannot delete a placement that has nodes or images.
• After deleting a placement, it is not automatically unassigned from virtual machines and volumes created from an image that has this placement. To clean up placements from VMs and volumes, use the --no-placements option for the vinfra service compute server set and vinfra service compute volume set commands described in the Administrator Command Line Guide.

To create a placement

1. Open the Compute > Nodes > Placements tab, and then click Create placement.
2. Specify a name for the new placement. The name should clearly state the distinctive feature of nodes in the placement. For example, Microsoft Windows Server license.

3. In the Nodes section, click Add, and then select the nodes to be included in the placement. VMs already hosted on the selected nodes will not be automatically assigned this placement.

   

4. [Optional] In the Images section, click Add, and then select images to be added to the placement. VMs created from such images will automatically be added to the placement.

   

5. Click Create.

The new placement will appear in the list.

To add a node to a placement

1. On the Compute > Nodes > Placements tab, click the required placement.
2. Go to the Nodes tab, and then click Add.
3. Select the nodes to be included in the placement, and then click Add.

To add an image to a placement

1. Open the Compute > Nodes > Placements tab, and then click the required placement.
2. On the Properties tab, click Add in the Images section.
3. Select one or more images, and then click Add.

When you select this image while creating a VM, the corresponding placement will be selected automatically.

To rename a placement

1. On the Compute > Nodes > Placements tab, select the required placement, and then click Edit on its right pane.
2. Enter a new name, and then click Save.

To delete a placement

1. On the Compute > Nodes > Placements tab, select the required placement.
2. On the Properties tab, remove added images, if any.
3. Go to the Nodes tab and remove added nodes and images, if any.
4. On the placement right pane, click Delete.
5. In the confirmation window, click Delete placement.