Cloudware Basics - Guide to Cloud Computing for Business and Technology Managers - page 264

User responsibility

SaaS PaaS IaaS

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Interface Interface Interface

Application Application Application

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Operating system Operating system Operating system

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r
v
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c
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Hypervisor Hypervisor Hypervisor

Computing service Computing service Computing service

Storage service Storage service Storage service

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Network Network Network

Local infrastructure Local infrastructure Local infrastructure

FIGURE 13.2
Portfolio of services for the three cloud delivery models.

cloud user can request allocation of virtual resources, which are then allo-
cated by the IaaS provider on the hardware (generally without any manual
intervention). The cloud user can manage the virtual resources as desired,
including installing any desired OS, software, and applications. Therefore,
IaaS is well suited for users who want complete control over the software
stack that they run; for example, the user may be using heterogeneous soft-
ware platforms from different vendors, and they may not like to switch to a
PaaS platform where only selected middleware is available. Well-known IaaS
platforms include Amazon EC2, Rackspace, and RightScale. Additionally,
traditional vendors such as HP, IBM, and Microsoft offer solutions that can
be used to build private IaaS.