capacity-reservations

name	capacity-reservations
description	Capacity Reservation Groups (CRG) — guarantee capacity for critical/DR VMs

Capacity Reservations

When to use this skill

• DR target region needs guaranteed capacity
• Frequent AllocationFailed on critical SKU

Key concepts

• CRG reserves capacity for a specific SKU + region + (optional) zone.
• Charged for reserved capacity whether VMs are deployed into it or not.
• Decoupled from RI — you can have capacity without a financial reservation, and vice versa.
• Critical for DR — without CRG, failover into the target region can hit AllocationFailed.
• Plan reservations per-zone for AZ DR.

Azure CLI examples

az capacity reservation group create -g <rg> -n crg-dr --location westus2 --zones 1 2 3
az capacity reservation create -g <rg> --capacity-reservation-group crg-dr \
  -n cr-z1 --sku Standard_D8s_v5 --capacity 10 --zone 1

Common pitfalls

• Forgetting CRG capacity is billed regardless of VM presence.
• Reserving a SKU you can't actually deploy to (capacity-constrained zone).
• Skipping CRG for DR and discovering allocation failures during a real failover.

References

• Microsoft Learn: search for "Capacity Reservations 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.