So What Is a Virtual Data Centre Really?
Lately you might have been hearing Cloud marketers endorsing a form of data centre that seems to be more than just a Cloud. Enter, the “Virtual Data Centre”. Could it be more virtual than the Cloud? Is it also a data centre? It sounds like the next level in co-location but in fact it’s still as good as it gets – which is nothing to be sniffed at.
We know about the different cloud deployment models at data centres: public cloud; private cloud; and the hybrid cloud, which combines both private and public clouds, usually from different data centres to facilitate cloud storage and processing. The Virtual Data Centre is capable of providing all three models within co-location data centres. The infrastructure can be segregated and made private to each customer but still allows each resident to expose their environment publicly.
Typical cloud users merely use data centre facilities for cloud-based applications – think Software as a Service (SaaS). Instead the Virtual Data Centre is virtualised right down to infrastructure-level and made available to customers – think Infrastructure as a Service (IaaS) and Platform as a Service (PaaS). The cloud provider is responsible for the CAPEX of the entire data centre kit i.e. physical servers and VMs, storage partitioning, network infrastructure and load balancers, however, the onus is on the cloud user to configure their partition of it.
More about PaaS
Within the stack of cloud-computing, PaaS adds an extra layer of abstraction to that of SaaS. Where in SaaS cloud providers manage infrastructure used by applications being served from the Cloud, in PaaS the software development effort is provided with a framework (Microsoft’s Azure is prominent in this market). This framework entails middleware, operating systems and development and deployment services.
- The main benefits. The management of hardware and software complexities is usually taken care of by the cloud provider while also making a stack of development tools and APIs available to the customer for efficient software development and delivery.
- Drawbacks. Some capabilities offered by the provider might be beyond its users’ skill level and will therefore go unused.
More about IaaS
IaaS further abstracts the physical infrastructure made available to the user by the cloud provider. Popular hypervisors that are able to achieve this kind of resource pooling include VMware’s ESX and Microsoft’s Hyper-V and others, such as the open-source Xen and Oracle’s VirtualBox.
- The main benefits. The customer is relieved from the responsibility of managing the physical infrastructure and is immensely scalable as a result. Any associated CAPEX resides with the cloud provider who usually bills their customers based on the amount of resources allocated and used to them.
- Drawbacks. Handling the complexity of configuring Virtual Private Networks (VPN) is done by the customer and so is operating system and application management, such as installations, upgrades, and licensing.