Storage vMotion warning while selecting the datastore cluster "Complete compatibility validation cannot be performed on the selected storage."

Products

• VMware vSphere ESXi
• VMware vCenter Server 8.0

Issue/Introduction

Symptoms:

• During the migration of a Virtual Machine's storage (Storage vMotion) to a Datastore Cluster using the vSphere Client, the warning message appears in the compatibility section of the migration wizard:

"Complete compatibility validation cannot be performed on the selected storage. Only storage that is not part of datastore clusters with Storage DRS enabled can be completely validated."

• Despite this warning, the Next button remains active, and the migration wizard permits the process to continue.

Environment

• VMware vSphere 7.x

• VMware vSphere 8.x

Cause

This message is an expected, informational alert rather than a software defect or system error.

When a standard, standalone datastore is selected, vCenter immediately validates constraints such as available capacity, block sizes, and host accessibility. However, when a Datastore Cluster with Storage DRS (SDRS) enabled is targeted, the final placement decision (i.e., the specific underlying datastore where the Virtual Machine will reside) is deferred to the SDRS algorithmic engine.

Because the vSphere Client UI lacks the exact destination datastore information while the wizard is open, a strict, upfront compatibility check cannot be performed. Instead, the UI generates an alert indicating that complete validation will occur server-side during the actual task execution.

Resolution

No corrective action is required, as this an expected behaviour by design. Two methods are available to proceed, depending on deployment preferences:

Option 1: Proceed with the Migration (Recommended) The warning can be safely bypassed, allowing Storage DRS to handle the placement autonomously.

1. Leave the Datastore Cluster selected and click Next to finish the wizard.

2. Upon task initialization, the Storage DRS engine automatically evaluates the cluster, performs the necessary compatibility and capacity checks on the backend, and executes the placement.

Note: If a legitimate compatibility issue exists (e.g., insufficient space across the entire cluster), the SDRS placement task will gracefully fail in the Recent Tasks pane before any data is moved.

Option 2: Manually Select a Datastore (vSphere 8 Workflow) If strict, upfront UI validation is required before initiating a task, the UI can be forced to display individual datastores by temporarily disabling SDRS for the specific Virtual Machine.

1. In the storage selection screen of the migration wizard, select the target Datastore Cluster.

2. Check the box labelled Disable Storage DRS for this virtual machine.

3. The UI will then reveal the individual underlying datastores. Select the desired standalone datastore.

4. A green "Compatibility checks succeeded" message will appear after the system completes the check.

5. Proceed with the migration.

Note: This method overrides the Storage DRS placement algorithm for this specific migration. Re-enabling SDRS automation for this Virtual Machine may be necessary at a later time to ensure participation in future automated storage load-balancing.