Understanding the different types of cloud services

Cloud Computing
Understanding the different types of cloud computing

Cloud computing is the biggest thing to hit the IT world since the World Wide Web. Concerns over its security, deployment and the use of virtualisation have made companies question whether it is right for them.

Here we look at three facts:

  • The cloud can be very secure
  • It's not always virtual
  • You can use a mixture of vendors, both public and private, for maximum availability, scaling, load balancing and disaster recovery.

1. The cloud can be very secure

Of course it's not as simple as that. The Cloud is a very broad term used to describe a resilient, scalable system providing services for a business. It actually breaks down into four types: public, private, community and hybrid and the security levels vary.

i. Public cloud is usually a large shared environment, which is often free to use, but expandable for a premium, e.g. Dropbox, Soundcloud and Evernote. Your account can be secured with two-step verification (a password and secure code received in a text) and is often protected by SSL encryption.

However, the security is not usually sufficient to comply with industry standards, such as ISO27001.

ii. Private cloud is dedicated to, or operated by a single organisation. This is much more secure; can be hosted internally, or in a data centre; and can be managed in either instance by a third party.

When hosted within the office (and correctly firewalled) only staff can access this system. If hosted by a data centre, a dedicated connection to your office ensures maximum security against a breach. Access is also usually restricted to the data floor without prior authorisation and identification on entrance.

iii. Community cloud is a larger system, usually hosted by a data centre, which is shared between a group of companies with mutual interests and standards, e.g. healthcare or finance organisations. Users would connect to the system via a secure, encrypted Virtual Private Network (VPN) to prevent a security breach.

iv. Hybrid cloud is a mixture two or more of the above models, linked together for data and application portability, but remaining separate entities. An example of hybrid cloud would be running business applications and storing data within a private cloud, but holding non-mission critical archives or shared storage in a public cloud to cut costs.

2. Cloud isn't always virtual

Many people consider cloud as virtual servers hosted 'somewhere'. To an extent this is right as 'somewhere' denotes a group of geographically diverse data centres located around the UK, or across the planet, and linked together with superfast, secure connections. However, virtual servers are not always a good fit for applications where physical servers are more efficient.

For example, if you are running database software, such as Microsoft SQL Server or MySQL, they require a high amount of resource to run. In a virtual environment, this would often mean that busy database servers would require a dedicated hypervisor, and separate physical disks from the other virtual machines.

In this instance, physical servers are included in the infrastructure, but are not hosting virtual machines. Instead, these servers are dedicated to the task of hosting the database and providing all the physical resource required to run smoothly and efficiently.

Some virtualisation management packages such as OnApp can even manage physical servers in a group. For resilience, data on these physical servers would be replicated to other physical servers in diverse data centres to ensure maximum integrity across the Cloud platform.

3. You can mix vendors

You can use a mixture of vendors, both public and private, for maximum availability, scaling, load balancing and disaster recovery.

Although one vendor can offer multiple data centres and diverse network connections with multiple providers, you can add redundancy by using more than one vendor, or hosting an environment at your office, which replicates the one in the data centre.

There are many different possible configurations of cloud using single or multiple vendors and varying levels of security and cost. Deciding where your data needs to be and how securely it needs to be stored can help when designing your system and choosing suppliers.

Deciding how many vendors you wish to involve will then be based on your design as well as assessing the financial risk if you experience downtime.


There are many misconceptions in the industry putting people off moving to the cloud. Hopefully this article has helped bust some of those myths and given you more confidence in the technology.

  • Jack Bedell-Pearce has over 12 years of commercial, operational and technical experience. He is responsible for the day-to-day running of 4D Data Centres, a cloud-based solutions provider for SMEs in the South East.