You can use vCenter Server tagging to tag VMs and associated clusters, respectively, with specific tags. These tags define - for a given cluster - the set of VMs that is placed with that cluster and remains within the cluster. When the system runs an optimization action, it uses VM-to-cluster tag matching to ensure that VMs are moved to - or stay with - the appropriate cluster.

To edit Business Intent values, you must have privileges for Administration -> Configuration -> Workload Placement Settings -> Edit.

Using Tags for Cluster Flexibility

When configuring custom data centers and clusters without tags, you configure CDCs as relatively homogeneous. All cluster resources must support, for example, the same OS or the same security requirements so that optimization actions do not place VMs in the wrong cluster.

The tagging approach enables you to define zones of infrastructure within cluster boundaries. For example, you can ensure that during workload optimization actions, Windows VMs are moved only to Windows-licensed clusters and Oracle VMs are moved only to Oracle-licensed clusters. Similarly, you can enable tiers of service in an application, where "Tier 1" VMs are moved only to Tier 1 clusters running business-critical applications. Other examples include separating VMs according to OS, or creating network boundaries.

VMs and clusters can be tagged with more than one tag. VMs with multiple tags are placed only on clusters with all matching tags.

Note:

VM-to-cluster tagging is not the same as host-based VM tagging. See Business Intent - Host-Based Virtual Machine Placement.

vCenter Server tags are implemented as key:value labels that enable operators to add meta-data to vCenter Server objects. In vCenter Server terminology, the key is the tag category and the value is the tag name.

Using this construct, the tag OS: Linux can indicate a cluster or VM that is assigned to the category OS with a tag name of Linux. For complete information on vCenter Server tagging capabilities, refer to the vCenter Server and Host Management guide.

The system provides several preset categories at the Business Intent Workspace:

  • Operating System

  • Environment

  • Tier

  • Network

  • Other

These categories represent potential business intent in gathering VMs into various associations. You are free to remove a category or add a new one that works for your environment.

Using this construct, the tag OS: Linux can indicate a cluster or VM that is assigned to the category OS with a tag name of Linux. For complete information on vCenter Server tagging capabilities, refer to the vCenter Server and Host Management guide.

In vRealize Operations Manager, you assign category and name tags in Policies, at the Business Intent workspace.

Tagging Considerations

  • You can choose either cluster-tag-based placement or host-based placement in the same data center or custom data center, but not both. If you select cluster-tag-based placement, host tags are ignored. Conversely, if you choose host-tag-based placement, cluster tags are ignored.

  • If a VM is tagless, the system attempts to move it to a tagless cluster.

Tag Implementation Example: Cluster Zones of Service and Licensing

The following example shows how an administrator assigned tags to clusters and VMs to create zones within a data center:

Using vCenter Server, the administrator sets up these tag categories and associated tag names:

  • Environment: Production, Staging, Dev

  • Service Tier: Gold, Silver

  • Licensing: Oracle

Data Center A includes 15 clusters. The administrator tags the clusters and VMs in those clusters as follows:

Cluster

Environment

Service Tier

Licensing

1

Production

Gold

2, 3

Production

Silver

4, 5

Production

Oracle

6

Staging

Gold

7, 8

Staging

Silver

9, 10

Staging

Oracle

11

Dev

Gold

12, 13

Dev

Silver

14, 15

Dev

Oracle

Opening the vRealize Operations Manager policies to Tag-Based VM Placement in the Business Intent window, the administrator prioritizes the Environment: Production and Service Tier: Gold category-tag combinations. Because the Optimization policies emphasize balance, clusters with those tags are balanced first.