Single-system image

From Wikipedia, the free encyclopedia

This article or section is missing citations or needs footnotes. Using inline citations helps guard against copyright violations and factual inaccuracies. (April 2007)

To comply with Wikipedia's lead section guidelines, the introduction of this article may need to be rewritten. Please discuss this issue on the talk page and read the layout guide to make sure the section will be inclusive of all essential details.

Single-system image or SSI is when the operating system maintains its state as a single copy of data in memory. Each system call on a processor can obtain data by load/store to that single copy. For example, a system that has an individual boot disk that operates using 1, 2, 512 or more processors. The largest number of processors ever to operate under a single system image was 1,024 processors.^[1]

Contents 1 SSI in computer clusters 2 Examples of SSI clustering systems 3 See also 4 References

[edit] SSI in computer clusters

In distributed computing, a SSI cluster is a system in which multiple networks, distributed databases or servers appear to the user as a single system. In other words, the operating system environment is shared by all nodes in the system.

[edit] Examples of SSI clustering systems

• Amoeba (inactive)
• The long-term goal of DragonFly BSD
• Genesis
• Inferno
• Kerrighed
• Nomad (inactive)
• OpenSSI
• Open-Sharedroot - shared root Cluster from ATIX
• Plan 9
• Plurix
• Sprite (inactive)
• Hewlett-Packard's TruCluster
• OpenVMS
• LinuxPMI

Other clustering systems may provide certain SSI characteristics without appearing as a single virtual system:

• Beowulf Distributed Process Space (BProc)
• Mosix/openMosix (inactive)

[edit] See also

• Computer clusters
• Diskless Shared Root Cluster

[edit] References