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.

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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.