spot-vms

name	spot-vms
description	Spot VMs and Spot VMSS — eviction policy, max price, workload fit

Spot Vms

When to use this skill

• Batch/CI/render/ML training
• Stateless workers in VMSS

Key concepts

• Spot price varies; eviction occurs when capacity is needed or price exceeds your max.
• Eviction policy: Deallocate (preserves disks, can be restarted) vs Delete (cleaner for ephemeral).
• Eviction type: Capacity only (cheaper, fewer evictions) vs Price or Capacity.
• Use --max-price -1 to pay up to PAYG (only evicted for capacity).
• Spot VMSS supports a fall-back policy via mixed PAYG instances.

Azure CLI examples

az vm create -g <rg> -n <name> --image Ubuntu2204 \
  --priority Spot --eviction-policy Deallocate \
  --max-price -1 --size Standard_D4s_v5

Common pitfalls

• Running stateful single-instance workloads on Spot — eviction = downtime.
• Not handling Scheduled Events / IMDS eviction signal for graceful shutdown.
• Forgetting that Premium OS disks survive eviction with Deallocate policy — Delete avoids the cost.

References

• Microsoft Learn: search for "Spot Vms Azure VM" on https://learn.microsoft.com

---

Validation-first: verify every Azure fact against the Microsoft Learn MCP server (cite the Learn URL); Learn overrides built-in knowledge. If no Learn MCP server is configured, flag the answer ⚠️ unverified and mark specs as indicative. Analysis only — verify against Microsoft documentation before applying.