Cloud computing, a new internet-based technology, has
been widely envisioned as the most promising technology of IT
enterprise. It manages and schedules the computing resources
through network, and constitutes a large computing resources
pool which can provide service to users on their demand. The
network is called “cloud”. Resources in cloud it seems that can be
extended unlimitedly, got anytime, used on-demand and paid
according to apply. This feature is often called using IT service as
water or electricity. It is a distributed processing, parallel
processing and Grid Computing development. Together with this
new technology, lots of business models which can be described of
“X as a service (Xaas)” where X could be infrastructure, platform,
software etc [1]. The most representative commercial cloud
platforms are Amazon Elastic Compute Cloud (EC2) and
Amazon Simple Storage System [2], Google App Engine [3], and
Microsoft Azure [4]. All of these service providers have achieved
great success in business. The increasing network bandwidth and
reliable yet flexible network connections make it even possible
that users can now subscribe high quality services from data and
software that reside solely on remote data centers.
In Cloud Computing Environment storage as a service is the one
of the major service provided by the cloud, those user wants to store
their processed data and applications can be maintained by the third
party cloud service provider in the virtualized pools on the data
centers. User need to pay for the storage capacity consumed from the
service provider. User can be provided an option to store the data onpremise or off-premise based on their data security concern. However
cloud service provider can virtualize the resources depends on the user
requirement of the storage on cloud