Which storage replication option provides the least cost?

Locally Redundant Storage (LRS) is the most cost-effective replication option among those listed. LRS keeps multiple copies of your data within a single datacenter in a region, which provides a level of redundancy while minimizing costs. This is particularly beneficial for scenarios where data redundancy is necessary, but the operational expense must be kept low.

LRS protects against hardware failures and ensures data durability by replicating your data three times in the same location. Since it doesn't incur additional costs associated with replicating data across geographically distant locations, as seen in options like Geo Redundant Storage (GRS) or Read-Access geo-redundant storage (RA-GRS), it provides a lower-cost solution for data resiliency.

In contrast, GRS and RA-GRS involve replicating data to a secondary region, which significantly increases the cost due to the additional storage and data transfer expenses incurred. Zone Redundant Storage (ZRS), while useful for providing high availability by spreading data across availability zones, also tends to be more expensive than LRS due to the complexity and redundancy across multiple zones. Therefore, LRS stands out as the least expensive option for ensuring data reliability within a single geographical area.