There are no signs of the debate on the merits of cloud computer abating – and rightly so.

The desire to square the circle of the lauded merits of cloud computing (flexibility, cost and scalability) with the nagging concern of its capacity to deliver services securely will continue to preoccupy the minds of CIOs, CEOs and industry analysts alike.

Does the latest piece of commentary from Gartner help? The analyst house's latest projection argues that by 2012 more than 50 per cent of data centre workloads that can be virtualised, will be virtualised; however, their damning verdict is that "60 per cent of virtualised servers will be less secure than the physical servers they replace".

So, in terms of the debate of this impending boom/doom, does this take us back to square one? Not necessarily.  This latest reality check from Gartner is welcome. Regular readers of the Loop will know that we at Lumison have long advocated the merits of a hybrid model, the private cloud.

The merits of a private as opposed to the public cloud are pretty straightforward: whereas both models enable SMEs to scale up without the need to procure or invest in infrastructure, the private cloud provides SMEs with the peace of mind of owning their data safely in a third party datacentre, complete with dedicated 24x7 business support.

With this dedicated service come certain advantages. Whereas private clouds can be subjected to rigorous third party audits (which may be necessary for their own, or their customers’ legal and regulatory needs), finding any public cloud operators that will support such audits and provide the relevant audit documentation on behalf of their clients is more than a tricky task.

Furthermore, given that both technology and human beings tend to be fallible, when things go wrong the service level agreements and commercial rebates provided by most large-scale cloud offerings are often, at best, hazy. From a technical side no promises can be made regarding I/O transactions per sec, or latency between application servers and the storage arrays.

Essentially, the question remains for SMEs wanting to re-evaluate their on-premise services: can the public cloud provide businesses with the reassurance that existing level of performance will be maintained?

Given the existing security concerns, companies' auditing needs, and demands for watertight SLAs, transferring critical business applications to the public cloud will only appeal to certain businesses

The reality is that the public cloud requires refinement and maturation. It has showed us how we can work differently; in the meantime the private cloud show us how we should be working.