Server/Storage Virtualization and Grid Computing ◾ 439
that contains clusters as its nodes is the NSF TeraGrid [GRI200301]; another example, the World
Wide Grid, has many nodes that are clusters located in organizations such as NRC Canada, AIST-
Japan, N*Grid Korea, and University of Melbourne. Although cluster management systems such
as Platform’s Load Sharing Facility, Veridian’s Portable Batch System, or Sun’s Sun Grid Engine
can deliver enhanced distributed computing services, they are not grids themselves. ese clus-
ter management systems have centralized control, complete knowledge of system state and user
requests, and complete control over individual components (such features tend not to be charac-
teristic of a grid proper) [FOS20020 ...