Cloud storage means that your data is kept in a remote storage location maintained by a third party, instead of on your computer´s hard drive, or other local and private storage infrastructure. Access to your data is immediate via an Internet connection, yet the burden of keeping it safe and dealing with your increasing needs for storage is handled by a third party.
Traditional professional digital data storage, on the other hand, requires maintenance of hard disks, the electrical power necessary to keep them spinning, a safe risk-free physical space and a cooling system that prevents them from meltdowns. There are also security personnel that must be hired to prevent unauthorized access to hard disks, and technical staff who keep the storage system, redundant and consistently up and running so no files are lost or accessed by unauthorized parties.
Cloud storage vs traditional data storage
Cloud storage offers many advantages over traditional data storage. It is flexible, since it allows access to data from anywhere and can expand as needs for storage grow. It is also extremely simple and cost-efficient, since there is no hardware to maintain, no staff to employ.
Cloud storage has become so popular that there are hundreds of solutions on the market, with more cropping up daily. Some are small operators that keep customer data in a single-room, while others fill warehouses with storage equipment. As end customer the difference you see is in the price, service quality, storage limit and speed of retrieval.
How it works
The most basic cloud storage system is a single data server connected to the Internet. A client – that is, a computer subscribing to a cloud storage service – sends copies of its files over the Internet to the data server, which records the information. How and where the data is recorded is unknown to the end user. To access the cloud-stored data, the user accesses the remote cloud server through a Web-based interface or specialized API. The server then either sends the files back to the client or allows the client to access and manipulate the files directly on the server.
In order to minimize data loss risks, cloud storage systems usually rely on hundreds of data servers, storing client information on multiple machines at once. This is called redundancy. Without sufficient redundancy, a cloud storage system cannot ensure clients that they will have immediate access to their information for as long as it is stored with the third party. But redundancy has a side effect, which is that makes data deletion insecure or incomplete: when a deleting request is made, this may not result on the final wiping of the data. [In fact, it never does] Data deletion might even be impossible (and unwanted from the customer´s point of view), either because extra copies are stored but unavailable when the request is done, or because the disk that user wants to erase also stores data from other customers.
Erasing data requires as much effort as to store them in the cloud, so the storage cloud provider always limits its expenses un-assigning the storage space used and letting it as “available”. In most of the File Systems, data are not erased until its storage space is required to store new data. With this strategy, private data remains orphan in the cloud storage infrastructure during some long and unknown time.
Most cloud provider systems store client data on multiple servers that use different power supplies, network connections, cooling services, etc. This is called fault tolerance, since it ensures that data remains intact even in the case of failure of one server. It is this feature that makes cloud storage unique from any other traditional digital office solution.
Sources: Extract from Jorge´s Dávila White Paper “Cloud Storage Flexibility, Cost–saving, Scalability, Convenience, and Security?”
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