Horizontal Scaling

Scale-out, often referred to as horizontal scaling, means adding arrays to a group. Performance and capacity scale linearly as you add arrays to the group. Grouping multiple arrays so that they can be managed as one entity provides significant manageability benefits, because it appears as if you are managing a single large array. Scale-out simplifies load balancing and capacity management, as well as hardware and software life-cycle management.

From an organizational standpoint, scale-out establishes a group of merged systems upon which storage pools can be developed. Volumes are created within pools that can span multiple physical arrays. A volume might exist on one array or span multiple arrays in a group by virtue of how the pool is configured.

Scale-out is a peer-to-peer technology where each array can operate independently, but can be managed as a single pool of storage. With scale-out, you not only add more disk and flash memory, but also CPU, system memory, network links, and so on.

Scale-out requires that all arrays in a group have the same version of array software installed.