Editing Single system image (section)

{{Short description|Cluster dedicated operating system}}
In [[distributed computing]], a '''single system image''' ('''SSI''') cluster is a [[cluster (computing)|cluster]] of machines that appears to be one single system.<ref name=Pfister1998>{{Citation
 | last = Pfister
 | first = Gregory F.
 | year = 1998
 | title = In search of clusters
 | isbn = 978-0-13-899709-0
 | publisher = Prentice Hall PTR
 | location = Upper Saddle River, NJ
 | oclc = 38300954
 | url-access = registration
 | url = https://archive.org/details/insearchofcluste00pfis
 }}</ref><ref name=Buyya2001>{{citation
 |author1=Buyya, Rajkumar |author2=Cortes, Toni |author3=Jin, Hai | year = 2001
 | title = Single System Image
 | journal = International Journal of High Performance Computing Applications
 | volume = 15
 | issue = 2
 | pages = 124
 | doi = 10.1177/109434200101500205
 |s2cid=38921084 | url = http://www.buyya.com/papers/SSI-CCWhitePaper.pdf
}}</ref><ref name=Healy2016>{{citation
 |author1=Healy, Philip |author2=Lynn, Theo |author3=Barrett, Enda |author4=Morrison, John P. | year = 2016
 | title = Single system image: A survey
 | journal = Journal of Parallel and Distributed Computing
 | volume = 90-91
 | pages = 35–51
 | doi = 10.1016/j.jpdc.2016.01.004
 | url = https://cora.ucc.ie/bitstream/handle/10468/4932/PH_Single_SV2016.pdf
|hdl=10468/4932 }}</ref> The concept is often considered synonymous with that of a [[distributed operating system]],<ref>
{{Citation
 | title = Distributed systems: concepts and design
 | year = 2005
 |author1=Coulouris, George F |author2=Dollimore, Jean |author3=Kindberg, Tim | isbn = 978-0-321-26354-4
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 | page = 223
 | url = https://books.google.com/books?id=d63sQPvBezgC&dq=%22distributed+operating+system%22&pg=PA223
}}</ref><ref>{{Citation
 |author1=Bolosky, William J. |author2=Draves, Richard P. |author3=Fitzgerald, Robert P. |author4=Fraser, Christopher W. |author5=Jones, Michael B. |author6=Knoblock, Todd B. |author7=Rashid, Rick | contribution = Operating System Directions for the Next Millennium | title = 6th Workshop on Hot Topics in Operating Systems (HotOS-VI) | place = Cape Cod, MA | pages = 106–110 | date = 1997-05-05| doi = 10.1109/HOTOS.1997.595191  | citeseerx = 10.1.1.50.9538 
|isbn=978-0-8186-7834-9 |s2cid=15380352 }}</ref> but a single image may be presented for more limited purposes, just [[job scheduling]] for instance, which may be achieved by means of an additional layer of software over conventional [[Operating system|operating system image]]s running on each [[Node (networking)|node]].<ref>{{Citation
 | title=Grid And Cluster Computing
 | author= Prabhu, C.S.R.
 | isbn=978-81-203-3428-1
 | publisher=Phi Learning
 | year=2009
 | pages=256
 | url=https://books.google.com/books?id=EIVdVtGHv-0C&dq=%22distributed+operating+system%22+%22single+system+image%22&pg=PA177
}}</ref> The interest in SSI clusters is based on the perception that they may be simpler to use and administer than more specialized clusters.

Different SSI systems may provide a more or less complete [[illusion]] of a single system.