Grid storage is a general term for any approach to storing data that employs multiple self-contained storage nodes interconnected so that any node can communicate with any other node without the data having to pass through a centralized switch. Each storage node contains its own storage medium, microprocessor, indexing capability, and management layer. Typically, several nodes may share a common switch, but each node is also connected to at least one other node cluster. Several topologies have been designed and tested, including the interconnection of nodes in a hypercube configuration, similar to the way nodes are interconnected in a mesh network.
Grid storage offers at least three advantages over older storage methods. First, grid storage introduces a new level of fault-tolerance and redundancy. If one storage node fails or a pathway between two nodes is interrupted, the network can reroute access another way or to a redundant node. This reduces the need for online maintenance, which practically eliminates downtime. Secondly, the existence of multiple paths between each pair of nodes ensures that the storage grid can maintain optimum performance under conditions of fluctuating load. Thirdly, grid storage is scalable. If a new storage node is added, it can be automatically recognized by the rest of the grid. This reduces the need for expensive hardware upgrades and downtime.