Microsoft Azure Fundamentals (AZ-900)Describe Azure architecture and servicesHard
A company is designing a highly available application in Azure that requires a redundant power supply, cooling, and networking for its virtual machines. They also want to ensure that if a hardware failure occurs, their VMs are automatically moved to a healthy host. Which Azure architectural component should they use to achieve this level of physical isolation and resilience within a single datacenter?
- AResource Groups
- BAzure Regions
- CAvailability Zones
- DAvailability Sets
Show answer & explanationAnswer & explanation
Correct answer: D. Availability Sets
Availability Sets provide logical grouping of VMs within a datacenter to ensure that they are deployed across multiple isolated hardware nodes (fault domains) and updated at different times (update domains). This protects against single points of failure within the datacenter and automatically moves VMs to healthy hosts in case of hardware failure.
Why the other options are wrong
- A. Resource Groups are logical containers for Azure resources and do not provide physical isolation or resilience.
- B. Azure Regions are geographically separate areas, providing the highest level of disaster recovery, but the question asks for resilience 'within a single datacenter'.
- C. Availability Zones provide physical separation across distinct datacenters within a region, offering higher resilience than Availability Sets, but the question specifies 'within a single datacenter'.
Availability Sets
A logical grouping capability for VMs that ensures that the VMs are placed across multiple isolated hardware nodes in a datacenter. This protects against failures within the datacenter.
- Distributes VMs across fault domains (physical server racks).
- Distributes VMs across update domains (groups that can be rebooted together).
- Provides resilience against single points of failure within a datacenter.
- Ensures automatic movement to healthy hosts during hardware failures.
Memory trick: Availability Sets for datacenter, Zones for regions, Regions for global.