Scale-out operation failing during "vmaffinityrule" task

Products

• VMware Cloud Director

Issue/Introduction

VM/VNF instantiation on Telco Cloud Platform (TCA/TCP) or a vCloud Director (vCD) environment fails during the resource placement stage when creating a distributed affinity rule. The deployment fails with the error:

Job ID:
XXXXXX
Object:
position-anti-affinity
Type:
vmaffinityrule
Status:
Failed
Organization:
XXXXXX
Initiator:
XXXXX
Start Time:
11/11/2025, 12:34:21 AM
Completion Time:
11/11/2025, 12:31:19 AM
Service Namespace:
com.vmware.vcloud
Details:
[ XXXXXX ] The operation failed because no suitable resource was found.

Environment

10.3.3

Cause

The deployment fails because the placement service cannot find any host (hub) that satisfies the cumulative list of constraints. The immediate trigger is an overly restrictive or incorrectly configured Distributed Anti-Affinity Rule.

When the system attempts to place a new VM and enforce the rule (e.g., VM must be on a host separate from an existing VM), the constraint limits the available hosts to zero, especially when combined with existing CPU/Memory reservations or secondary constraints like Storage Policy requirements.

Resolution

The primary resolution is to review and correct the Affinity and Anti-Affinity rules active on the target resource cluster.

1. Review DRS Affinity Rules in vCenter:

   • Log into the vCenter Server managing the resource cluster.

   • Navigate to the Cluster > Configure tab > vSphere DRS > Affinity/Anti-Affinity Rules.

   • Examine the rules that involve the VMs or VM Groups associated with the failing deployment.

   • Action: Temporarily disable or edit overly restrictive rules (e.g., "Separate Virtual Machines" rules that affect the deployment group).

2. Review VNF/CNF Manager Rules (if applicable):

   • If the rules are being managed by a Telco Cloud Automation (TCA-M) or similar system, ensure the rule logic in the VNF Descriptor (VNFD) or template is correct and does not create an impossible placement scenario (e.g., trying to separate 5 VMs onto 4 available hosts).

3. Check for Storage/Host Constraints (Secondary Check):

   • Although the Affinity Rule was the root cause, the log showed other failures (disabled storage containers, storage policy mismatch). These must be corrected as they reduce the overall resource pool, making it easier for a restrictive affinity rule to cause a complete failure.

   • Ensure all intended datastores are enabled and support the required storage policy.

4. Re-attempt Instantiation: Once the relevant affinity rules are corrected, the tenant should retry the instantiation/scale-out task.

Notes: It is suggested to engage with your Vendor/Application owner so they can review these steps during the scale-out / instantiation

Additional Information

 

• When troubleshooting placement issues, it is best practice to address constraints in the following order: 1. Hard Affinity/Anti-Affinity Rules > 2. Storage Policy/Datastore Constraints > 3. CPU/Memory Reservations.

• Temporarily setting DRS to Fully Automated with a less-aggressive migration threshold can sometimes provide more flexibility for placement if rules are dynamic, but this is generally a workaround, not a permanent fix.