AZ104-Q: VM availability within a single region
Q: You must keep a set of VMs available during planned maintenance (updates) and tolerate individual hardware failures, within one region, at the lowest complexity. Which provides fault-domain and update-domain protection inside one region?
- A) A single VM in an availability zone
- B) An availability set ✓
- C) Just autoscale
- D) A public load balancer
Answer: B — Availability set. An availability set spreads VMs across fault domains (isolated power/network/nodes for hardware failure) and update domains (for Azure planned maintenance), all within one region. Availability zones give higher resilience across datacenters but in one region and don’t provide update-domain separation the same way; for a simple single-region workload, an availability set is the classic answer.
Why it helps
Availability set = FD + UD within a region; Availability zone = datacenter isolation; VMSS = scale + availability.
Related
availability-set · availability-zones · virtual-machine-scale-set