Cost Optimization: Reclaiming vSAN Capacity with TRIM/UNMAP and Orchestrated Batch Restarts

On vSAN, reclaimed space is not automatic unless TRIM/UNMAP is enabled and applied correctly. VMware guidance recommends batch power cycles for existing VMs to avoid cluster-wide performance impact.

Source KB: https://knowledge.broadcom.com/external/article/326595/procedure-to-enable-trimunmap.html

Orchestrator action: batch VM power-cycle scheduler (post-UNMAP enable)

Goal: after enabling TRIM/UNMAP, restart existing VMs in controlled batches to apply the setting without creating an I/O spike.

Workflow steps (VMware Aria Orchestrator)

• Create a workflow: 'vSAN - Batch VM Power Cycle for UNMAP Adoption'
• Inputs: vmFolder (VC:Folder), batchSize (number, default 10), waitMinutesBetweenBatches (number, default 10)
• Step 1: Enumerate powered-on VMs in the target folder (or tag-based selection).
• Step 2: Power cycle VMs in batches of batchSize (graceful guest shutdown if possible).
• Step 3: Wait waitMinutesBetweenBatches before continuing to the next batch.
• Step 4: Log completed VMs and failures; output a completion report for change records.

Expected outcome

UNMAP adoption happens safely, reducing vSAN capacity waste while keeping workload impact predictable.