Cloud Storage
Cloud storage
Cloud storage:
Cloud storage is a model of computer data storage in which the digital data
is stored in logical pools. 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 and accessible, and the physical
environment 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
service, a web service application programming interface (API) or by
applications that utilize 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 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 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 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, Dropbox,
and Pinterest. In 2005, Box 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 in terms of accessible interfaces,
near-instant elasticity and scalability, multi-tenancy, and metered resources.
Cloud storage services can be utilized from an off-premises service (Amazon S3)
or deployed on-premises (ViON Capacity Services).
Cloud storage typically refers to a hosted object storage service, but the
term has broadened to include other types of data storage that are now
available as a service, like block storage.
Object storage services like Amazon S3, Oracle Cloud Storage and Microsoft
Azure Storage, object storage software like Openstack Swift, object storage
systems like EMC Atmos, EMC ECS and Hitachi Content Platform, and distributed
storage research projects like OceanStore and VISION Cloud are all examples of
storage that can be hosted and deployed with cloud storage characteristics.
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 durable through the
creation of versioned copies
·
Typically eventually
consistent with regard to data replicas
·
Highly fault tolerant
through redundancy and distribution of data
Adavantages:
·
Businesses using cloud
storage can cut their energy consumption by up to 70% making them a more green
business.
·
Companies need only pay for
the storage they actually use, typically an average of consumption during a
month. This does not mean that cloud storage is less expensive, only that it
incurs operating expenses rather than capital expenses.
·
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 maintenance tasks,
such as purchasing additional storage capacity, are offloaded to the
responsibility of a service provider.
·
Storage availability and
data protection 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.
·
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 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 protocol. It can function as a central file
server for organizations with multiple office locations.
·
Cloud storage can be used
for copying virtual machine images 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.
Potential concerns:-
Data security:
Outsourcing data storage increases the attack
surface area.
1. 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 can be used when disposing of data (on a
disk).
2. 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.
3. 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.
4. 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.
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:
1. Go bankrupt.
2. Expand and change their focus.
3. Be purchased by other larger companies.
4. Be purchased by a company headquartered in or move to a country that
negates compliance with export restrictions and thus necessitates a move.
5. 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 and
data in transit 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 and
YouTube sites it has been compared to.
·
The legal aspect, from a
regulatory compliance standpoint, is of concern when storing files domestically
and especially internationally.
Options:
There are several options available to avoid such issues. One option is to
use a private cloud instead of a public cloud (there are as well providers that
offer private cloud storage). Another option is to ingest data in encrypted
format where the key is hold within your on premise infrastructure. Access is
often by use of cloud storage gateways that are on premise. Such gateways have options
not only to encrypt and compress the data prior of transfer but as well mirror
the storage across multiple cloud storage providers and remove the risk of a
single providers shutdown. Gateways offer as well the option to cache data on a
most recently used algorithm on premise. Along with data analytics data is
cached and fetched on a most valuable form instead of recently used only form.
Google Storage
Google Cloud Storage is a RESTful online file
storage web service for storing and accessing data on Google Cloud Platform
infrastructure. The service combines the performance and scalability of
Google's cloud with advanced security and sharing capabilities. It is an
Infrastructure as a Service (IaaS), comparable to Amazon S3 online storage
service. Contrary to Google Drive and according to different service
specifications, Google Cloud Storage appears to be more suitable for
enterprises.
Feasibility:
User activation is resourced through the API Developer Console. Google
Account holders must first access the service by logging in and then agreeing
to the Terms of Service, followed by enabling a billing structure.
Design:
Google Storage stores objects (originally limited to 100 GiB, currently up
to 5 TiB) that are organized into buckets (as S3 does) identified within each
bucket by a unique, user-assigned key. All requests are authorized using an
access control list associated with each bucket and object. Bucket names and
keys are chosen so that objects are addressable using HTTP URLs:
Features:
Google Storage offers four storage classes, identical in throughput,
latency and durability. The four classes, Multi-Regional Storage, Regional
Storage, Nearline Storage, and Coldline Storage, differ in their pricing,
minimum storage durations, and availability.
·
Interoperability - Google
Storage is interoperable with other cloud storage tools and libraries that work
with services such as Amazon S3 and Eucalyptus Systems.
·
Consistency - Upload
operations to Google Storage are atomic, providing strong read-after-write
consistency for all upload operations.
·
Access Control - Google
Storage uses access control lists (ACLs) to manage object and bucket access. An
ACL consists of one or more entries, each granting a specific permission to a
scope. Permissions define what someone can do with an object or bucket (for
example, READ or WRITE). Scopes define who the permission applies to. For
example, a specific user or a group of users (such as Google account email
addresses, Google Apps domain, public access, etc.
·
Resumable Uploads - Google
Storage provides a resumable data transfer feature that allows users to resume
upload operations after a communication failure has interrupted the flow of
data.