What is High Availability Storage?

High-availability storage (HA storage) is a storage system that is continuously operational or provides at least 99% uptime.
Redundancy is a key feature of HA storage, as it allows data to be kept in more than one place and eliminates a single points of failure (SPOF). HA storage systems are often used in virtual server environments as a security feature to protect critical virtual machines.

HA storage arrays require at least two controllers in case one is lost. For disaster recovery, HA storage requires a secondary storage system to hold critical data and applications the business needs if its primary storage system goes offline. This is often done by replicating data to another storage system at another site.

Why is Highly Available Storage So Important?

Common downfalls like disk failures, instance failures, network failures and availability zone failures will inevitably cause downtime and disrupt operations in the cloud.
With high availability storage, continuous operation is seemless. A redundant storage environment ensures that if one of the servers crashes, the workload is immediately directed to another server without requiring administrative intervention.

Source: Internet