Azure Data Redundancy

Data Redundancy ensures multiple copies of data is available for restoring in case of any hardware failures.

Redundancy gives us the higher availability and durability for your data. So the trade off is between the cost and the availability. 

Every region has multiple Availability Zones, and every Availability Zones have multiple Data Center. And every Data Center has different racks in it.

Redundancy in the primary region

• Locally-redundant storage LRS, that means making a copy within the same Data Center. 
• Zone - redundant storage ZRS, copies in three availability zones (AZ)

Redundancy in secondary region

• Geo-redundant storage GRS - LRS +Asynchronous copy to secondary region
• Geo-zone redundant storage 

For read access to the secondary region, configure storage account -

• Read access Geo-redundant storage (RA- GRS)
• Read access Geo-zone redundant storage  (RA- GZRS)