Cloud storage
   HOME

TheInfoList



OR:

Cloud storage is a model of
computer data storage Computer data storage is a technology consisting of computer components and recording media that are used to retain digital data. It is a core function and fundamental component of computers. The central processing unit (CPU) of a compute ...
in which the digital data is stored in logical pools, said to be on "the cloud". The physical storage spans multiple servers (sometimes in multiple locations), and the physical environment is typically owned and managed by a hosting company. These cloud storage providers are responsible for keeping the data
available In reliability engineering, the term availability has the following meanings: * The degree to which a system, subsystem or equipment is in a specified operable and committable state at the start of a mission, when the mission is called for at a ...
and
accessible Accessibility is the design of products, devices, services, vehicles, or environments so as to be usable by people with disabilities. The concept of accessible design and practice of accessible development ensures both "direct access" (i. ...
, and the physical environment secured, protected, and running. People and organizations buy or lease storage capacity from the providers to store user, organization, or application data. Cloud storage services may be accessed through a colocated
cloud computing Cloud computing is the on-demand availability of computer system resources, especially data storage ( cloud storage) and computing power, without direct active management by the user. Large clouds often have functions distributed over mu ...
service, a web service application programming interface (API) or by applications that use the API, such as cloud desktop storage, a cloud storage gateway or Web-based content management systems.


History

Cloud computing is believed to have been invented by Joseph Carl Robnett Licklider in the 1960s with his work on
ARPANET The Advanced Research Projects Agency Network (ARPANET) was the first wide-area packet-switched network with distributed control and one of the first networks to implement the TCP/IP protocol suite. Both technologies became the technical fou ...
to connect people and data from anywhere at any time. In 1983, CompuServe offered its consumer users a small amount of disk space that could be used to store any files they chose to upload. In 1994,
AT&T AT&T Inc. is an American multinational telecommunications holding company headquartered at Whitacre Tower in Downtown Dallas, Texas. It is the world's largest telecommunications company by revenue and the third largest provider of mobile te ...
launched PersonaLink Services, an online platform for personal and business communication and entrepreneurship. The storage was one of the first to be all web-based, and referenced in their commercials as, "you can think of our electronic meeting place as the cloud."
Amazon Web Services Amazon Web Services, Inc. (AWS) is a subsidiary of Amazon that provides on-demand cloud computing platforms and APIs to individuals, companies, and governments, on a metered pay-as-you-go basis. These cloud computing web services provide d ...
introduced their cloud storage service AWS S3 in 2006, and has gained widespread recognition and adoption as the storage supplier to popular services such as
SmugMug SmugMug is a paid image sharing, image hosting service, and online video platform on which users can upload photos and videos. The company also facilitates the sale of digital and print media for amateur and professional photographers. On Apri ...
,
Dropbox Dropbox is a file hosting service operated by the American company Dropbox, Inc., headquartered in San Francisco, California, U.S. that offers cloud storage, file synchronization, personal cloud, and client software. Dropbox was founded in 2007 ...
, and
Pinterest Pinterest is an American image sharing and social media service designed to enable saving and discovery of information (specifically "ideas") on the internet using images, and on a smaller scale, animated GIFs and videos, in the form of pinboard ...
. In 2005,
Box A box (plural: boxes) is a container used for the storage or transportation of its contents. Most boxes have flat, parallel, rectangular sides. Boxes can be very small (like a matchbox) or very large (like a shipping box for furniture), and can ...
announced an online file sharing and personal cloud content management service for businesses.


Architecture

Cloud storage is based on highly virtualized infrastructure and is like broader
cloud computing Cloud computing is the on-demand availability of computer system resources, especially data storage ( cloud storage) and computing power, without direct active management by the user. Large clouds often have functions distributed over mu ...
in terms of interfaces, near-instant elasticity and
scalability Scalability is the property of a system to handle a growing amount of work by adding resources to the system. In an economic context, a scalable business model implies that a company can increase sales given increased resources. For example, a ...
,
multi-tenancy Software multitenancy is a software architecture in which a single instance of software runs on a server and serves multiple tenants. Systems designed in such manner are "shared" (rather than "dedicated" or "isolated"). A tenant is a group of us ...
, and
metered A measuring instrument is a device to measure a physical quantity. In the physical sciences, quality assurance, and engineering, measurement is the activity of obtaining and comparing physical quantities of real-world objects and events. Esta ...
resources. Cloud storage services can be used from an off-premises service (
Amazon S3 Amazon S3 or Amazon Simple Storage Service is a service offered by Amazon Web Services (AWS) that provides object storage through a web service interface. Amazon S3 uses the same scalable storage infrastructure that Amazon.com uses to run its ...
) or deployed on-premises (ViON Capacity Services). There are three types of cloud storage: a hosted
object storage Object storage (also known as object-based storage) is a computer data storage that manages data as objects, as opposed to other storage architectures like file systems which manages data as a file hierarchy, and block storage which manages data a ...
service,
file storage In computing, file system or filesystem (often abbreviated to fs) is a method and data structure that the operating system uses to control how data is stored and retrieved. Without a file system, data placed in a storage medium would be one larg ...
, and
block storage In computing (specifically data transmission and data storage), a block, sometimes called a physical record, is a sequence of bytes or bits, usually containing some whole number of records, having a maximum length; a ''block size''. Data thu ...
. Each of these cloud storage types offer their own unique advantages. Examples of object storage services that can be hosted and deployed with cloud storage characteristics include
Amazon S3 Amazon S3 or Amazon Simple Storage Service is a service offered by Amazon Web Services (AWS) that provides object storage through a web service interface. Amazon S3 uses the same scalable storage infrastructure that Amazon.com uses to run its ...
, Oracle Cloud Storage and Microsoft Azure Storage, object storage software like
Openstack Swift OpenStack is a free software, free, open-source software, open standard cloud computing platform. It is mostly deployed as Cloud computing#Infrastructure as a service (IaaS), infrastructure-as-a-service (IaaS) in both public and private clouds w ...
, object storage systems like
EMC Atmos EMC Atmos is a cloud storage services platform developed by EMC Corporation. Atmos can be deployed as either a hardware appliance or as software in a virtual environment. The Atmos technology uses an object storage architecture designed to manage ...
, EMC ECS and Hitachi Content Platform, and distributed storage research projects like OceanStoreS. Rhea, C. Wells, P. Eaton, D. Geels, B. Zhao, H. Weatherspoon, and J. Kubiatowicz, Maintenance-Free Global Data Storage. IEEE Internet Computing , Vol 5, No 5, September/October 2001, pp 40–49

and VISION Cloud. Examples of file storage services include
Amazon Elastic File System Amazon Elastic File System (Amazon EFS) is a cloud storage service provided by Amazon Web Services (AWS) designed to provide scalable, elastic, concurrent with some restrictions, and encrypted file storage for use with both AWS cloud services ...
(EFS) and Qumulo Core, used for applications that need access to shared files and require a file system. This storage is often supported with a
Network Attached Storage Network-attached storage (NAS) is a file-level (as opposed to block-level storage) computer data storage server connected to a computer network providing data access to a heterogeneous group of clients. The term "NAS" can refer to both the tech ...
(NAS) server, used for large content repositories, development environments, media stores, or user home directories. A block storage service like
Amazon Elastic Block Store Amazon Elastic Block Store (EBS) provides raw block-level storage that can be attached to Amazon EC2 instances and is used by Amazon Relational Database Service (RDS). It is one of the two block-storage options offered by AWS, with the other be ...
(EBS) is used for other enterprise applications like databases and often require dedicated, low latency storage for each host. This is comparable in certain respects to direct attached storage (DAS) or a
storage area network A storage area network (SAN) or storage network is a computer network which provides access to consolidated, block-level data storage. SANs are primarily used to access data storage devices, such as disk arrays and tape libraries from ser ...
(SAN). Cloud storage is: * Made up of many distributed resources, but still acts as one, either in a federated or a cooperative storage cloud architecture * Highly fault tolerant through redundancy and distribution of data * Highly durable through the creation of versioned copies * Typically eventually consistent with regard to data replicas


Advantages

* Companies need only pay for the storage they actually use, typically an average of consumption during a month, quarter, or year. This does not mean that cloud storage is less expensive, only that it incurs operating expenses rather than capital expenses. * Businesses using cloud storage can cut their energy consumption by up to 70% making them a more green business. * Organizations can choose between off-premises and on-premises cloud storage options, or a mixture of the two options, depending on relevant decision criteria that is complementary to initial direct cost savings potential; for instance, continuity of operations (COOP), disaster recovery (DR), security (PII, HIPAA, SARBOX, IA/CND), and records retention laws, regulations, and policies. * Storage availability and
data protection Information privacy is the relationship between the collection and dissemination of data, technology, the public expectation of privacy, contextual information norms, and the legal and political issues surrounding them. It is also known as data pr ...
is intrinsic to object storage architecture, so depending on the application, the additional technology, effort and cost to add availability and protection can be eliminated. * Storage maintenance tasks, such as purchasing additional storage capacity, are offloaded to the responsibility of a service provider.ZDNet, Nasuni Cloud Storage Gateway By Dan Kusnetzky, June 1, 2010

/ref> * Cloud storage provides users with immediate access to a broad range of resources and applications hosted in the infrastructure of another organization via a web service interface. * Cloud storage can be used for copying
virtual machine image A disk image, in computing, is a computer file containing the contents and structure of a disk volume or of an entire data storage device, such as a hard disk drive, tape drive, floppy disk, optical disc, or USB flash drive. A disk image is us ...
s from the cloud to on-premises locations or to import a virtual machine image from an on-premises location to the cloud image library. In addition, cloud storage can be used to move virtual machine images between user accounts or between data centers. * Cloud storage can be used as natural disaster proof backup, as normally there are 2 or 3 different backup servers located in different places around the globe. * Cloud storage can be mapped as a local drive with the
WebDAV WebDAV (Web Distributed Authoring and Versioning) is a set of extensions to the Hypertext Transfer Protocol (HTTP), which allows user agents to collaboratively author contents ''directly'' in an HTTP web server by providing facilities for con ...
protocol. It can function as a central file server for organizations with multiple office locations.


Potential concerns


Data security

Outsourcing data storage increases the attack surface area. # When data has been distributed it is stored at more locations increasing the risk of unauthorized physical access to the data. For example, in cloud based architecture, data is replicated and moved frequently so the risk of unauthorized data recovery increases dramatically. Such as in the case of disposal of old equipment, reuse of drives, reallocation of storage space. The manner that data is replicated depends on the service level a customer chooses and on the service provided. When encryption is in place it can ensure confidentiality.
Crypto-shredding Crypto-shredding is the practice of 'deleting' data by deliberately deleting or overwriting the encryption keys. This requires that the data have been encrypted. Data may be considered to exist in three states: data at rest, data in transit an ...
can be used when disposing of data (on a
disk Disk or disc may refer to: * Disk (mathematics), a geometric shape * Disk storage Music * Disc (band), an American experimental music band * ''Disk'' (album), a 1995 EP by Moby Other uses * Disk (functional analysis), a subset of a vector sp ...
). # The number of people with access to the data who could be compromised (e.g., bribed, or coerced) increases dramatically. A single company might have a small team of administrators, network engineers, and technicians, but a cloud storage company will have many customers and thousands of servers, therefore a much larger team of technical staff with physical and electronic access to almost all of the data at the entire facility or perhaps the entire company. Decryption keys that are kept by the service user, as opposed to the service provider, limit the access to data by service provider employees. As for sharing multiple data in the cloud with multiple users, a large number of keys has to be distributed to users via secure channels for decryption, also it has to be securely stored and managed by the users in their devices. Storing these keys requires rather expensive secure storage. To overcome that, key-aggregate cryptosystem can be used. # It increases the number of networks over which the data travels. Instead of just a local area network (LAN) or storage area network (SAN), data stored on a cloud requires a WAN (wide area network) to connect them both. # By sharing storage and networks with many other users/customers it is possible for other customers to access your data. Sometimes because of erroneous actions, faulty equipment, a bug and sometimes because of criminal intent. This risk applies to all types of storage and not only cloud storage. The risk of having data read during transmission can be mitigated through encryption technology. Encryption in transit protects data as it is being transmitted to and from the cloud service. Encryption at rest protects data that is stored at the service provider. Encrypting data in an on-premises cloud service on-ramp system can provide both kinds of encryption protection. There are several options available to avoid security issues. One option is to use a private cloud instead of a public cloud. Another option is to ingest data in encrypted format where the key is held within on-premise infrastructure. To this end, access is often by use of on-premise cloud storage gateways that have options to encrypt the data prior of transfer.


Longevity

Companies are not permanent and the services and products they provide can change. Outsourcing data storage to another company needs careful investigation and nothing is ever certain. Contracts set in stone can be worthless when a company ceases to exist or its circumstances change. Companies can: # Go bankrupt. # Expand and change their focus. # Be purchased by other larger companies. # Be purchased by a company headquartered in or move to a country that negates compliance with
export restrictions Export restrictions, or a restriction on exportation, are limitations on the quantity of goods exported to a specific country or countries by a Government. Export restrictions could be aimed at achieving diverse policy objectives such as environ ...
and thus necessitates a move. # Suffer an irrecoverable disaster.


Accessibility

* Performance for outsourced storage is likely to be lower than local storage, depending on how much a customer is willing to spend for WAN bandwidth * Reliability and availability depends on wide area network availability and on the level of precautions taken by the service provider. Reliability should be based on hardware as well as various algorithms used. * Its a given a multiplicity of data storage.


Other concerns

* Security of
stored data Data storage is the recording (storing) of information (data) in a storage medium. Handwriting, Phonograph record, phonographic recording, magnetic tape, and optical discs are all examples of storage media. Biological molecules such as RNA a ...
and
data in transit Data in transit, also referred to as data in motion and data in flight, is data en route between source and destination, typically on a computer network. Data in transit can be separated into two categories: information that flows over the publi ...
may be a concern when storing sensitive data at a cloud storage provider * Users with specific records-keeping requirements, such as public agencies that must retain electronic records according to statute, may encounter complications with using cloud computing and storage. For instance, the U.S. Department of Defense designated the Defense Information Systems Agency (DISA) to maintain a list of records management products that meet all of the records retention, personally identifiable information (PII), and security (Information Assurance; IA) requirements * Cloud storage is a rich resource for both hackers and national security agencies. Because the cloud holds data from many different users and organizations, hackers see it as a very valuable target. * Piracy and copyright infringement may be enabled by sites that permit filesharing. For example, the CodexCloud ebook storage site has faced litigation from the owners of the intellectual property uploaded and shared there, as have the
GrooveShark Grooveshark was a web-based music streaming service owned and operated by Escape Media Group in the United States. Users could upload digital audio files, which could then be streamed and organized in playlists. The Grooveshark website had a sea ...
and
YouTube YouTube is a global online video sharing and social media platform headquartered in San Bruno, California. It was launched on February 14, 2005, by Steve Chen, Chad Hurley, and Jawed Karim. It is owned by Google, and is the second mo ...
sites it has been compared to. * The legal aspect, from a regulatory compliance standpoint, is of concern when storing files domestically and especially internationally. * The resources used to produce large data centers, especially those needed to power them, is causing nations to drastically increase their energy production. This is leads to further climate damaging implications.


Hybrid cloud storage

Hybrid cloud storage is a term for a storage infrastructure that uses a combination of on-premises storage resources with cloud storage. The on-premises storage is usually managed by the organization, while the public cloud storage provider is responsible for the management and security of the data stored in the cloud. Hybrid cloud storage can be implemented by an on-premises cloud storage gateway that presents a file system or object storage interface which the users can access in the same way they would access a local storage system. The cloud storage gateway transparently transfers the data to and from the cloud storage service, providing low latency access to the data through a local cache. Hybrid cloud storage can be used to supplement an organization's internal storage resources, or it can be used as the primary storage infrastructure. In either case, hybrid cloud storage can provide organizations with greater flexibility and scalability than traditional on-premises storage infrastructure. There are several benefits to using hybrid cloud storage, including the ability to
cache Cache, caching, or caché may refer to: Places United States * Cache, Idaho, an unincorporated community * Cache, Illinois, an unincorporated community * Cache, Oklahoma, a city in Comanche County * Cache, Utah, Cache County, Utah * Cache County ...
frequently used data on-site for quick access, while inactive
cold data In computer storage, cold data refers to data that is rarely accessed, therefore considered "cold". Cold data is the opposite of hot data, which is data that is frequently accessed. To optimize storage costs, cold data can be stored on lower perform ...
is stored off-site in the cloud. This can save space, reduce storage costs and improve performance. Additionally, hybrid cloud storage can provide organizations with greater redundancy and fault tolerance, as data is stored in both on-premises and cloud storage infrastructure.


See also


References

{{DEFAULTSORT:Cloud Storage Network file systems Outsourcing