Cloud Storage

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Cloud storage is a model of networked online storage where data is stored on virtualized pools of storage which are generally hosted by third parties. Hosting companies operate large data centers; and people who require their data to be hosted buy or lease storage capacity from them and use it for their storage needs. The data center operators, in the background, virtualize the resources according to the requirements of the customer and expose them as storage pools, which the customers can themselves use to store files or data objects. Physically, the resource may span across multiple servers.


Cloud storage services may be accessed through a web service application programming interface (API), or through a Web-based user interface.

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Cloud Storage Architecture

Cloud storage has the same characteristics as cloud computing in terms of agility, scalability, elasticity and multi-tenancy. According to ComputerWeekly, it is believed by many experts to have been invented by Joseph Carl Robnett Licklider in the 1960's. Since the sixties, cloud computing has developed along a number of lines, with Web 2.0 being the most recent evolution. However, since the internet only started to offer significant bandwidth in the nineties, cloud computing for the masses has been something of a late developer.


One of the first milestones for cloud computing was the arrival of Salesforce.com in 1999, which pioneered the concept of delivering enterprise applications via a simple website. The services firm paved the way for both specialist and mainstream software firms to deliver applications over the internet. Another notable mention would be FilesAnywhere who also in 1999 helped pioneer cloud based storage services that also enable users to securely share files online. Both of which continue to offer those services still today.


It is difficult to pin down a canonical definition of cloud storage architecture, but object storage is reasonably analogous. Cloud storage services like Amazon S3, cloud storage products like EMC Atmos, and distributed storage research projects like OceanStore are all examples of object storage and infer the following guidelines.


Cloud storage is:

• made up of many distributed resources, but still acts as one
• highly fault tolerant through redundancy and distribution of data
• highly durable through the creation of versioned copies
• typically eventually consistent in regards to data replicas

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