Cloud Computing - Cloud Data Management - page 11

Table 2.1 Feature similarities and differences between related technologies and cloud computing
Technologies Differences Similarities

Virtualization Cloud computing is not only about

virtualizing resources, but also about
intelligently allocating resources for
managing competing resource demands
of the customers.

Both isolate and abstract the
low-level resources for
high-level applications.

Autonomic
computing

The objective of cloud computing is focused
on lowering the resource cost rather than
to reduce system complexity as it is in
autonomic computing.

Both interconnect and integrate
distributed computing
systems.

Grid computing Cloud computing however also leverages

virtualization to achieve on-demand
resource sharing and dynamic resource
provisioning.

Both employ distributed resources
to achieve application-level
objectives.

Utility
computing

Cloud computing is a realization of utility
computing.

Both offer better economic
benefits.

and cloud computing in short, while details of related technologies are discussed as
following [ 239 ]:

Virtualization

Virtualization is a technology that isolates and abstracts the low-level resources
and provides virtualized resources for high-level applications. In the context of
hardware virtualization, the details of physical hardware can be abstracted away
with support of hypervisors, such as Linux Kernel-based Virtual Machine [ 33 ] and
Xen [ 48 ]. A virtualized server managed by the hypervisor is commonly called
a virtual machine. In general, several virtual machines can be abstracted from
a single physical machine. With clusters of physical machines, hypervisors are
capable of abstracting and pooling resources, as well as dynamically assigning
or reassigning resources to virtual machines on-demand. Therefore, virtualization
forms the foundation of cloud computing. Since a virtual machine is isolated from
both the underlying hardware and other virtual machines. Providers can customize
the platform to suit the needs of the customers by either exposing applications
running within virtual machines as services, or providing direct access to virtual
machines thereby allowing customers to build services with their own applications.
Moreover, cloud computing is not only about virtualizing resources, but also about
intelligent allocation of resources for managing competing resource demands of the
customers. Figure 2.2 illustrates a sample exploitation of virtualization technology
in the cloud computing environments [ 214 ].