Shared disk architecture

A shared disk architecture (SD) is a distributed computing architecture in which all disks are accessible from all cluster nodes. It contrasts with shared nothing architecture, in which all nodes have sole access to distinct disks. Multiple processors can access all disks directly via intercommunication network and every processor has local 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.