Cloud computing and virtualisation

BY BASIRAT ISHOLA

In this article, I will be focusing on cloud computing and virtualisation. It is important to first give an overview of these two technologies:

Cloud computing

Cloud computing is a relatively new technology that has become quite popular over a short period of time as a result of several advantages it offers to businesses and end-users generally. Cloud computing is a term that is generally used to describe the delivery of hosted services over the internet.

Its primary advantage has to do with cost reduction for organisations because it makes it possible for them to consume computer resources as a utility, in a way that is very similar to more traditional utilities like electricity, gas and water. Such that, instead of expending scarce resources to design, build and maintain extensive and expensive dedicated computer infrastructure, companies simply pay for what they consume.

Though there has been a lot of advancement in cloud computing, it is still generally broken down into three key service areas which include:

Infrastructure as a service (IaaS)

In the case of IaaS, it is common for the service providers to provide a virtual server instance and storage, alongside application program interfaces (APIs) that offer the opportunity to migrate workloads to a virtual machine (VM). Based on the agreement, the clients are usually given a specified storage capacity to meet their workload requirements. This can range from quite small to extremely large storage capacities.

Platform as a service (PaaS)

For this category, these service providers basically house tools required for the development of software. The users are able to access these tools via the internet through the use of APIs, web portals or gateway software. It is important to state that the fully developed software can thereafter be hosted by these service providers. Examples of PaaS providers include- Salesforce.com and Google App Engine.

Software as a service (SaaS)

The last but not the least sub-category of cloud computing is SaaS. Its primary function is to act as a distribution model, via which diverse software apps are delivered over the internet. They are usually referred to as web services. A popular example is Microsoft Office 365. The beauty of SaaS services is the ability to access the various software apps with one’s computer or any mobile device with internet access.

Virtualisation

In simple terms, virtualisation is more or less the duplication of a thing in a virtual form rather than its real physical version. This applies to things like an operating system, a server, a storage device or other network resources.

In the case of operating system virtualisation, we are dealing with a situation where software is employed to enable single hardware to run several operating system virtual images simultaneously.

This technology has been in existence for a while and its major advantage has to do with cost savings in the area of acquisition and maintenance of expensive infrastructure.

Just like we have in cloud computing, there are three core spheres of information technology where virtualisation holds sway, they include:

Network Virtualisation

It is quite similar to hard drive partitioning, which leads to easier file management. Here the bandwidth is split into several channels that are not linked to one another, hence enabling them to be assigned to a specific server or device in real-time, hence simplifying the otherwise complex nature of the network. This invariably leads to the easier management of the less complex parts.

Storage Virtualisation

In this case, physical storage from several network storage devices is pooled together in such a way that it resembles a single large storage device that is thereafter managed via a central console. This method of virtualisation is often deployed in storage area networks (SANs).

Server Virtualisation

This is in a way similar to storage virtualisation, only in this case we are dealing with server resources. The identities of the several physical server resources are shielded from the service users so that they do not have to deal with the complex details, but enjoy the added advantages of server resource sharing.

It is pertinent to state here that just like the case of cloud computing, virtualisation also draws much of its advantages from utility computing, which translates to cost savings as organisations only have to pay for what they use. There is also the added advantage of reduced infrastructural and personnel costs. It also improves scalability.

Similarities between cloud computing and virtualisation

Despite the extensive deployment and increasing popularity of both cloud computing and virtualisation, it is still quite common, even amongst those in the IT sector to have challenges differentiating one from the other. This is because these two technologies are concerned with reducing reliance on physical infrastructures, while also providing quite similar services.
The similarities between cloud computing and virtualisation are highlighted below:

• Virtual network – These two technologies enable the storage of applications, data, and software on a virtualised network.

• Limit physical infrastructure requirements – Both systems capitalise on the use of virtual elements to help greatly limit the need for acquisition and maintenance of physical infrastructures, which translates into extensive cost savings.

• Multiple access points – Another key similarity between virtualisation and cloud computing is the ability of end-users to access them from several locations and platforms. Both systems are (usually) accessible from multiple locations and platforms.

Advancements

The key area of research focus in virtualisation and cloud computing is security. There have been advances on this front. A case in point is the Lightweight Directory Access Protocol (LDAP). This was originally developed to improve security in virtual systems, but it can also be deployed in cloud computing to help buffer already existing security policies in cloud infrastructure.

Additionally, it enables users to remotely manage and operate within the infrastructure. It is quite obvious from the above that cloud computation is dependent on virtualisation in order to effectively function. They are very much intertwined due to their marked similarities, hence advancement in one invariably results in an improvement in the other.

Ishola, a lead data scientist and business intelligence specialist, writes from Lagos.