A shared-disk architecture (SD) is a distributed computing architecture in which the nodes share same disk devices but each node has its own private memory.[1] The disks have active nodes which all share memory in case of any failures.[2] In this architecture, the disks are accessible from all the cluster nodes. This architecture has quick adaptability to the changing workloads.[3] It uses robust optimization techniques. Multiple processors can access all disks directly via intercommunication network and every processor has local memory.
It contrasts with shared-nothing architecture, in which all nodes have sole access to distinct disks,[4] and with shared-memory, in which they also share memory.
Shared-disk has two advantages over Shared-memory. Firstly, each processor has its own memory, the memory bus is not a bottleneck; secondly, the system offers a simple way to provide a degree of fault tolerance.