Abstract
Single system image is a computing paradigm where a number of distributed computing
resources are aggregated and presented via an interface that maintains the illusion of
interaction with a single system. This approach encompasses decades of research using a
broad variety of techniques at varying levels of abstraction, from custom hardware and
distributed hypervisors through to specialized operating system kernels and user-level
tools. Existing classification schemes for SSI technologies are reviewed, and an updated
classification scheme is proposed. A survey of implementation techniques is provided
along with relevant examples. Notable deployments are examined and insights gained
from hands-on experience are summarised. Issues affecting the adoption of kernel-level
SSI are identified and discussed in the context of technology adoption literature.