Do you know when to use Geo Redundant Storage?

Data in Azure Storage accounts is protected by replication. Deciding how far to replicate it is a balance between safety and cost.

Figure: It is important to balance safety and pricing when choosing the right replication strategy for Azure Storage Accounts

Locally redundant storage (LRS)

• Maintains three copies of your data.
• Is replicated three times within a single facility in a single region.
• Protects your data from normal hardware failures, but not from the failure of a single facility.
• Less expensive than GRS
• Use when:
  • Data is of low importance – e.g. for test websites, or testing virtual machines
  • Data can be easily reconstructed
  • Data is non-critical
  • Data governance requirements restrict data to a single region

Geo-redundant storage (GRS)

• The default when you create storage accounts.
• Maintains six copies of your data.
• Data is replicated three times within the primary region, and is also replicated three times in a secondary region hundreds of miles away from the primary region
• In the event of a failure at the primary region, Azure Storage will failover to the secondary region.
• Ensures that your data is durable in two separate regions.
• Use when:
  • Data cannot be recovered if lost

Read access geo-redundant storage (RA-GRS)

• Replicates your data to a secondary geographic location (same as GRS)
• Provides read access to your data in the secondary location
• Allows you to access your data from either the primary or the secondary location, in the event that one location becomes unavailable.
• Use when:
  • Data is critical, and access is required to both the primary and the secondary regions

More information:

• Azure Storage Redundancy Option