Not all clouds are the same
The concepts of virtual private server and virtual data centre often get confused as the same solution, says velocity Group.
All clouds are not equal.
So says Jonathan Kropf, founder of Cloud On Demand, who points out that the term 'cloud' is being used as an overarching phrase for anything that may be 'hosted'.
According to Kropf, infrastructure as a service is starting to gain favour, both at an end-user level and within the IT reseller community.
Having capacity on demand for a multitude of applications and reasons, and on an opex basis, certainly has its advantages and appeal, he explains, adding that, typically, the offering consumed has been a virtual private server (VPS) solution as a cloud server. The other option, which is growing in popularity in the US and Europe, is the concept of a virtual data centre, he notes.
Often, Kropf explains, these two concepts get confused as the same solution - virtual private servers are designed as a low-cost entry point for cloud computing. The original use cases are around Web site hosting, FTP servers, light e-mail servers, secondary offsite data backup and secondary development environment.
"The concept is very much like ADSL - many users, using a single pool of white label, low-cost hardware resources that is carved up using any one of many virtualisation solutions. Less users on a particular server backend means better performance. It is up to the individual provider to determine the 'contention' ratio for these servers. Often this is not explained. The pressure will always be there to over-contend a resource pool in order to gain a price advantage," says Kropf.
Describing the key VPS technical aspects, he says a VPS is a single server and all servers are Internet-facing. "That means if you have two VPSes that need to communicate, they need to break out over the Internet to do so. This consumes the bandwidth allocation bundled with a VPS."
He adds that reboot is required to increase resources in a VPS and there is no firewalling. "Your server is published to the Internet. You are responsible for loading a firewall on that single server, thereby increasing your server load and requiring you to commit to more resources than you need to get your performance.
"Storage, although often stipulated as 'SAN' is SATA based 5 400 or 7 400 drive based. Looking at these points, you can see why the original use case for a VPS server still stands today. A high IO application, dependent on communication with another server, is going to prove problematic in this type of environment."
On virtual data centres, he says the question of how to run production applications in the cloud, with the same kind of control one would have in their physical data centre, has been unanswered for quite a while.
He adds that the concept of the software-defined data centre has enabled a complete shift in the way organisations view and interact with cloud servers.
"Now it is not a case of a single point server solution, but a pool of resources that you are able to allocate to an unlimited amount of servers in your virtual data centre, with control of networking and firewall given to you as the administrator."