AZ-104 Microsoft Azure Administrator Exam

Evaluate Redundancy Models

Azure Storage plays a vital role in safeguarding your data, primarily by utilizing redundancy to ensure data durability and availability. Multiple copies of your data are stored across the infrastructure to protect against various failures, such as hardware issues or natural disasters. Redundancy is a core feature to meet availability and durability objectives, even when things go wrong.

Redundancy Options

Azure Storage offers several redundancy options that cater to different needs:

• Locally Redundant Storage (LRS): This option replicates your data three times within a single datacenter in the primary region. It is the most cost-effective choice but provides the least protection, safeguarding only against server rack and drive failures.
• Zone-Redundant Storage (ZRS): ZRS enhances protection by copying data synchronously across three Azure availability zones within the primary region. It offers better availability and durability than LRS.
• Geo-Redundant Storage (GRS): This redundancy option asynchronously replicates data to a secondary geographic region, delivering protection against regional disasters.
• Read-Access Geo-Redundant Storage (RA-GRS): Similar to GRS, RA-GRS allows read access to the secondary region when the primary region experiences an outage.
• Geo-Zone-Redundant Storage (GZRS) and Read-Access Geo-Zone-Redundant Storage (RA-GZRS): These options offer the highest level of redundancy by merging the benefits of both ZRS and GRS, ensuring near-guaranteed availability and durability by spreading out data replication across various zones and regions.

Choosing the Right Redundancy

When deciding which redundancy model best suits your needs, several factors should be considered:

• Cost vs. Availability: While LRS is the least expensive, it offers minimal protection. ZRS, GRS, and RA-GRS enhance availability but come at higher costs.
• Replication Needs: Analyze whether data should be replicated within the same region (LRS, ZRS) or across different regions (GRS, RA-GRS, GZRS, RA-GZRS).
• Read Access Requirements: If ensuring read access during primary region outages is crucial for your application, RA-GRS or RA-GZRS are suitable choices.

Best Practices

To protect your data effectively:

• Isolate Resources: Use separate storage accounts for different types of data depending on their specific redundancy requirements.
• Plan for Failover: Develop a disaster recovery plan that incorporates a failover strategy to secondary regions.
• Monitor Costs: Keep an eye on the costs related to different redundancy options and manage them based on your budget and protection needs.

In conclusion, effectively evaluating Azure Storage redundancy models ensures your data remains durable and available even during disruptions. By thoroughly comparing options like LRS, ZRS, GRS, and RA-GRS, and considering factors like cost and read access requirements, you can select a redundancy model that best fits your unique scenario.