Business Continuity & Disaster Recovery Flashcards

An architect is evaluating SLA commitments for a multi-region Azure deployment. If each region has a 99.9% availability SLA, what is the composite availability when using active-active across two regions with automatic failover?

Answer: 99.99% — multiplicative improvement through redundancy

In an active-active or automatic failover configuration, the composite availability approaches 1 - (1-0.999)^2 = 99.9999%, commonly expressed as ~99.99%, because both regions must fail simultaneously for an outage.

Which Azure Storage redundancy option replicates data synchronously across three availability zones within the same region?

Answer: Zone Redundant Storage (ZRS)

Zone Redundant Storage (ZRS) replicates data synchronously across three Azure availability zones in the same region, protecting against datacenter-level failures within that region.

A company needs their Azure-hosted application to withstand the failure of an entire Azure region. Which redundancy strategy should the architect recommend?

Answer: Deploy across paired Azure regions with geo-replication

Deploying across paired Azure regions with geo-replication protects against entire regional failures, as Azure regional pairs are geographically separated and updates are staggered.

Which Azure service provides a managed solution for backing up Azure file shares with configurable snapshot schedules and retention policies?

Answer: Azure Backup for Azure Files

Azure Backup for Azure Files provides centralized, policy-driven backup with configurable snapshot schedules and retention periods directly integrated with Recovery Services vaults.

An architect needs to protect Azure virtual machines against accidental deletion and ransomware by ensuring backups cannot be deleted for a defined retention period. Which Azure Backup feature provides this?

Answer: Azure Backup immutable vault

Azure Backup immutable vault enforces a time-based retention lock that prevents backup data from being deleted or modified before the defined retention period expires, protecting against ransomware and insider threats.

During a DR drill, a team performs a failover from the primary Azure region to the secondary. After validating recovery, they want to reverse replication and fail back. In Azure Site Recovery terminology, what is this process called?

Answer: Reprotect and failback

After failover, you must 'reprotect' the VM (which reverses the replication direction from secondary back to primary), and then perform a failback to return workloads to the original primary region.

A global retail company needs a BCDR strategy for their Azure SQL Database that minimizes data loss and allows read scale during normal operations. Which solution best meets both requirements?

Answer: Azure SQL Database active geo-replication with readable secondary replicas

Active geo-replication creates continuously synchronized, readable secondary replicas in up to four other regions, providing near-zero RPO for DR and offloading read workloads to secondaries during normal operations.