Cloud Fundamentals

This blog would be discussed the simple definition of the cloud computing, its role and IT as services. Furthermore, what organisation should be considered before moving to cloud computing?

What is a cloud?


According to the cloud Security Alliance (CSA)- “cloud enhances collaboration, agility, scaling, and availability, and provides the potential for cost reduction through optimised and efficient computing”.

What is the cloud computing?

“Cloud computing enables ubiquitous, convenient, on-demand network access to a shared pool of configurable computing resources that can be rapidly provisioned and released with minimal management effort or services provider interaction” – according to the  NIST definition of cloud.

Why use cloud computing?



Five Major Characteristics of the Cloud:

Self-services: cloud consumers can provision and manage servers, systems, and resources through a single portal or developer API. There is also an On-Demand component which indicates that resources are always available to the customers.

Broad accessibility: Cloud services are delivered consistently. They are available and accessible through standard, heterogeneous platforms such as laptops, desktops, and mobile devices.

Shared:  Cloud resources are provided for maximum efficiency and then shared across many consumers in a multi-tenant model. This model optimises resources allocation and financial efficiency.

Elastic: Resources can scale based on usage, scaling up/down typically means that server resources allocation (CPU/RAM/Storage) can dynamically change. Scaling in/out is thought of as adding or subtracting host nodes to an application based on demand.

Measured metered: Usage is calculated based on what is consumed by the user. This is typically referred to as a” pay-as-you-go” model and is similar in concept to your basic home utilities, for instance, water and power.

Three Deployment models:

  1. Open public:

Cloud resources are typically rendered over the internet or an open network. Public cloud is typically owned and operated by commercial service providers who own and offer access to consumers, for example, AWS, Rack space, and Salesforce

 2. Hybrid

A combination of one or more public or private clouds bound together by a common fabric. This model allows consumers many options to meet their business requirement and fits the cloud to need.

3. Enterprise Private

Cloud resources built specially for an entity (group, organisation, company, and so on). Infrastructure can be hosted internally or externally and also managed internally or by a third party.

Cloud Services Delivery Methods:

Infrastructure as a service (IaaS)

Infrastructure as a service supply companies with computing resources as well as servers, storage, networking, and data centre space on a pay-per-use basis.

The benefits of IaaS

  • No need to invest in own hardware
  • Infrastructure scales on demand to support dynamic workloads
  • Flexible, innovative services available on demand

IaaS Examples: Amazon Web Services (AWS), Cisco Metapod, Microsoft Azure, Google Compute Engine (GCE), Joyent

Platform as a service (PaaS)

Platform as a service provides a cloud-based environment with everything required to maintain the complete lifecycle of building and conveying online (cloud) applications —without the cost and difficulty of buying and managing the essential hardware, software, provisioning, and hosting.

 The benefits of PaaS

  • Develop applications and grab to market faster
  • Deploy new web applications to the cloud in minutes
  • Reduce complexity with middleware as a service

   Enterprise PaaS Examples: Apprenda

Software as a service (SaaS)

Software as a service in cloud-based application system which run on remote computers that are owned and control by others and that connect to client’ computers via the Internet and, usually, a web browser

The benefits of SaaS

  • the user can sign up and rapidly start using innovative business apps
  • Apps and data are accessible from any connected computer
  • If your computer breaks, usually no data is lost as data is in the cloud
  • The service is able to dynamically scale to usage needs

SaaS Examples: Google Apps, Salesforce, Workday, Concur, Citrix GoToMeeting, Cisco WebEx .


IT as a service:

ITaaS is an operational and organisational shift to running IT like a business and optimising IT production for business consumption.

  • New technology models
  • New consumption models
  • New operational models

Before moving to cloud organisation need to consideration some factors:

Cloud is not a perfect solution and often comes with concerns and questions from the industry and consumers. Five areas where cloud providers typically have to address.

Security and Risk:  1. I f I move to the cloud, are my applications safe? Will I become a target for hackers?

  • Provider security posture
  • Governance
  • Application security
  1. Attacks that affect you, even though you aren’t the target: Users of public cloud run the risk of collateral damage, virus attacks, and services interruptions
  2. Incident response: In a cloud environment, you may not have control over how quickly incidents are handled.
  3. Visibility:
  • You may not be able to see what your provider is doing
  • You may not have visibility to your resources running in the cloud
  1. Multiple cloud vendors: Some cloud providers may actually be storing your data on a different cloud provider’s platform


  • Who can view my data?
  • Where does my data reside?
  • Will an unauthorised entity have access to my data?
  • How will my data be segregated?
  • How will my data be destroyed?
  • Where will it be physically located?
  • How will my data be treated during the move?

Cloud computing risks:

  • Data stored on third-party servers
  • Limited control
  • Inadequate security
  • System breaches
  • Compromised data
  • Legal problems

Compliance: 1. How do we ensure we are meeting all of our compliance and regulatory compliance policies?

  • Compliance can be an increased cost
  • Compliance may require a cloud services audit
  1. Audit and compliance risks
  • Security risks
  • Information risks
  • Billing risks
  • Contract risks

Vendor lock-in: How can we support business continuity and ensure seamless migration between cloud services?

  • Proprietary and incompatibility
  • Inefficient processes
  • Contract constraints
  • Fear of vendor lock-in is a major impediment to cloud service adoption
  • Many customers stay with a provider that doesn’t meet their needs, just to avoid a cumbersome migration process

Performance: How can I be sure I’m getting the right level of performance and services quality from the cloud?

  • Nosy neighbor
  • Provider capabilities
  • Resources disparity
  • An enterprise IT organisation acting as a cloud provider to users of its hybrids cloud need to guarantee services without the control over the performance of public cloud services in its environment.

Question: what could be the reasons that financial organisations are not interested in moving cloud computing?

Answer: a Financial organisation like banks, leasing, depository financial organisation is not keen to move cloud computing because of data security. Cloud computing service is not able provided 100 % data security, privacy and legal compliance as per financial intuition required,   and the main factor is that cloud services have provided the third party vendors so there is a risk that client transaction and financial information can be compromised with any third party and competitor or hackers.



Storage Technologies

This post I would like to overview about the different type of storage technologies including Direct-attached storage (DAS), Network storage, storage virtualization, flash technology and cloud computing, and the components and protocol that underlie those technologies.  Furthermore, the benefits and which type of environment would be best-suited for that technology.

Direct-attached storage (DAS):

DAS is the digital storage system that is directly connected to one computer or server without any storage network in between, and it is not accessible to other clients and servers machines. Example, Hard drive is the form of direct-attached storage for an individual user.  DAS can be a disk on a server, Disk in a client, group of disks internal or external to a server.

In the enterprise solution, individual disk or group of disks that are internal or external are directly attached to a server through SCSI, SATA and SAS interfaces.

DAS sample


  • ATA
  • SATA
  • eSATA
  • SCSI
  • SAS
  • FC

Benefit :

  • It can provide better performance than network storage because of the dedication server
  • Server does not need to traverse the network in order to read and write data
  • Proper utilisation of underlying storage during expansion of application server
  • It is one of the famous cost effective solutions for any small organisation

Best-suited environment:

  • Small business organisation or enterprise
  • Small or home office users
  • Localised file sharing with single or few servers in an infrastructure
  • Certain type of application that needs high performance


For the organisation that anticipates rapid data growth, it is important to keep in mind that DAS is limited in its scalability.

Criticised: An inefficient way to manage storage because DAS can’t be shared and it has not failover facilities if server crash occurs. However,  the advantages of the DAS has gained again as virtualization become mainstream.

Network-attached storage (NAS):

It is a kind of dedicated file storage devices that provides local-area network nodes with file-based shared storage through an Ethernet connection. NAS has a processor, Disk array using RAID technology for handling disk failure, the external disk can be connected to NAS system for additional storage. For managing and configured NAS devices do not need a keyboard or a monitor, it can be a browser-based utility program.

From both a cost perspective and an administrative perspective, network storage models such as NAS and SAN are more suited to high scalability requirement and can address the challenges inherent in a DAS implementation.


  • Ethernet switch
  • Own IP address
  • CFS
  • NFS

How a NAS system functions?

  • Each NAS must reside on the Local area network as an independent network node
  • On a network, the NAS system appears on a file server with an IP address
  • The NAS implements file services by using protocols of CFS and NFS
  • The application servers handle all the processing of data



  • NAS provide multiple clients to access the same files on the network
  • NAS appliances can be outfitted with larger disks or clustered together which provide both vertical scalability and horizontal scalability
  • File-based storage system that makes data available over the network
  • NAS relieves the server of storage and file sharing responsibility
  • NAS vendors with cloud storage provider may provide customer with an extra layer of redundancy for backup files
  • More flexible to data access

Best-suited Environment:

Ideal for business organisation who wants to

  • Easy to manage, Install and deploy
  • Implementing multiple clients at the file level to get access to faster data in a cost effective way
  • Consolidate DAS resources for better utilisation


Storage Area Network (SAN):

It is a dedicated high-speed network storage that interconnects and maintains shared pools of storage devices to multiple servers.  It allows each server to access shared storage even through disk drives directly attached to the server.  It is blocked based storage system that transfers data between servers and storage devices on request from the user end. A host sends out a block- based access request when it wants to access storage on the SAN.

SAN dia


  • Cabling
  • Host bus adapters (HBAs)
  • Switches

How does it function?

  • Each switch and storage system must be interconnected
  • Physical interconnections must support bandwidth level so that they can handle peak data activities effectively

The different type of SAN:

  • FC-SAN (Fibre Channel) – most common


  • iSCSI SAN – Standard IP-based storage access protocolUntitled1
  • FCoE SAN – Fibre Channel over Ethernet


Best suited environment:

  • High data growth Database and Imaging server
  • High volume Transaction processing
  • High performance and 24/7 operation

Storage Virtualization:

Storage virtualization consists of taking several physical storage devices and joining them to appear as one logical unit to manage.

The benefit of storage virtualization:

  • Increase storage utilisation: It is easier for an administrator to managing all of the spaces including in the pool apart from its location by pooling storage into a single resource. This permits for much better storage utilisation.
  • Simplify storage management: Storage management is also easier because virtualization storage can be managed from a single administrate console. A storage administrator can see utilisation trends and growth patterns more clearly and can make better upgrade or capacity planning decisions. Virtualization storage can be thinly provisioned or even dynamically provisioned (increasing or decreasing the storage on demand)
  • Increase storage flexibility: Virtualization storage is also flexible when storage space is decoupled from a physical disk or storage arrays. It’s simple to migrate and copy that virtual storage between systems or geographic locations. For example, the data can be migrated from an older storage system to a newer one for the better performance without making any adjustments to the application. Similarly, data can be copied to another local storage system for backup purposes or replicate to an off-suit location for disaster recovery purposes.

The advantage of flash storage:

  • Memory unit: Stored data
  • Access controller: Manages and controls access to the storage space on the memory unit


  • Superior speed
  • Reliable compare to traditional disk and unlike traditional disk, it uses electricity and read faster
  • Flexible, Cost-effective, Optimise storage

The advantage of Cloud computing:


Private cloud computing:


  • Relay heavy on own data and applications
  • Have a restricted data security and privacy requirement
  • Can run a need-generation cloud data center efficiently and effectively on own system.

Disadvantage: Organization has to purchases and maintains all software and infrastructure

Public cloud computing:


  • The services and infrastructure are rendered off-site over the internet and are open to public
  • It offers the greatest level of efficiency in shared resources
  • Users don’t need to purchases hardware, software, or any supporting infrastructure because those resources are owned and managed by providers

Disadvantage: Public cloud is more vulnerable than private cloud in term of security and reliability

Hybrid cloud computing: It is a combination of private and public options. It can be the best choice for an organisation who offers services that are tailored for the different vertical market because the business can use a public cloud to communicate and connect with their clients and keep own data secure within a private cloud.


  • With multiple providers offering the benefit of multiple deployment models
  • Users can keep each aspect of their business in the most efficient environment

Disadvantage: Users have to keep track of multiple different security platforms and ensure that all aspects of their business can communicate with each other.

Question: A CEO of the organisation comes to you for a storage solution for his company. As per his requirement, the company has 1200 employees, maintained 8 separate servers for 8 different applications, they have a file server, mail server, database server and in hours software server.  Their data growth rate is GIGAbytes per hours. What is the best solution you would give him and why?

Answer:  The best suggestion I would like to give him to reduce the number of physical servers by using the virtualization storage. It would help him to reduce managing and maintain cost, administrative and controlling server would be easier for the company. Based on his data growth rate and access to operation time Storage Area network SAN  would be best suited for that company because it allows each server to access shared storage even through disk drives directly connected. It is high-speed network storage and maintained a shared pool of multiple servers. It is the best solution for that company has usage data growth database server and live operation 24/7, also required high performance.