Grid Computing - Guide to Cloud Computing for Business and Technology Managers - page 245

The main resources that can be shared in a grid are
• Computing/processing power
• Data storage/networked file systems
• Communications and bandwidth
• Application software
• Scientific instruments
Grid middleware is specific software, which provides the necessary function-
ality required to enable sharing of heterogeneous resources and establish-
ing of virtual organizations. From a market perspective, Grid middleware
provides a special virtualization and sharing layer that is placed among
the heterogeneous infrastructure and the specific user applications using
it. Grid computing is basically the deployed grid middleware or the com-
puting enabled by grid middleware based on flexible, secure, coordinated
resource sharing among a dynamic collection of individuals, institutions,
and resources. Grid computing means on the one hand that heterogeneous
pools of servers, storage systems, and networks are pooled together in a vir-
tualized system that is exposed to the user as a single computing entity. On
the other hand, it means programming that considers grid infrastructure and
applications that are adjusted to it. Grid infrastructure refers to the combina-
tion of hardware and grid middleware that transforms single pieces of hard-
ware and data resources into an integrated virtualized infrastructure that
is exposed to the user as a single computer despite of heterogeneity of the
underlying infrastructure. Utility computing is the provision of grid comput-
ing and applications as a service either as an open grid utility or as a hosting
solution for one organization or VO. Utility computing is based on pay-per-
use business models.
Thus, grid computing is a new computing paradigm based on IT resource
sharing and on provisioning of IT resources and computing in a way similar
to how electricity is consumed today. It is enabled by specific grid middle-
ware provided on the market either as packaged or open-source software
or in the form of utility computing. The major potential advantages of grid
computing for an improved management of IT in companies can be sum-
marized as follows:
• Grids harness heterogeneous systems together into a single large
computer and, hence, can apply greater computational power to a
task and enable greater utilization of available infrastructure. In par-
ticular, with grid computing existing, underutilized resources can
be exploited better.
• Grid computing enables greater scalability of infrastructure by
removing limitation inherent in the artificial IT boundaries existing
between separate groups or departments.