Private cloud: Turning corporate datacentres into a global virtual machine

Is it set to take cloud computing by storm? Or just a storm in a teacup?
Written by Nick Heath on

Is it set to take cloud computing by storm? Or just a storm in a teacup?

While cloud computing may attract more than its fair share of hype, there's no doubting that the technology has already made significant inroads into the corporate IT landscape.

Vendors are now predicting the advent of what's been dubbed the private cloud, a set-up whereby a company can link up every datacentre it owns into a single virtualised computer that could potentially span the globe.

According to its proponents, the private cloud could pave the way for an organisation to pool the combined processing and storage power of its entire IT estate, allowing it to divert computing power and data to wherever they are needed across the globe.

This would open the door for organisations to usefully move virtual machines freely between datacentres located in different countries or even continents, for example allowing companies to use servers in Australia to process data based in the UK.

Private cloud could also provide the efficiency and flexibility that server and storage virtualisation brings to individual datacentres on a far greater scale.

cloud computing

Organisations could soon be consolidating their datacentres into a virtualised private cloud
(Photo credit: SoRaZG via Flickr under the following licence)

The large-scale virtual datacentre set-up would also create a more reliable IT infrastructure, say its advocates, as if one physical server fails the virtual machines running on that server can be automatically switched to run on another physical server with no disruption to end users.

Speaking at the recent EMC World 2010 conference, Brian Gallagher, president of EMC's virtualisation product division, said a network of global virtualised datacentres would allow enterprises to "non-disruptively move and relocate virtual machines, applications and the associated information with those applications".

"So customers can be working with SAP or Oracle or Microsoft applications in one datacentre and they can teleport those applications to another datacentre. This will give them the ability to not only balance workloads over distance but also to avoid natural disasters.

"Now you can envision...

...moving thousands of virtual machines across thousands of miles, or doing night batch processing in low-cost energy locations and having those changes or results immediately available in the production environment," Gallagher said.

Independent analyst Claus Egge said the private cloud model would provide the greatest benefit to international organisations with offices spread across the world looking to move corporate applications and workloads from one location to another across the globe.

"For instance, this would appeal to global finance organisations looking to move those workloads from one location to another, as work days ended and began across the world," he told silicon.com.

Quocirca analyst Clive Longbottom believes the global private cloud model could benefit businesses when it comes to carrying out certain tasks, such as streaming virtual desktops to thin client computers, by helping to balance demand for computing power between a global network of datacentres.

"There will be certain workloads where it makes a great deal of sense to be able to spread these around because it can free up resources where they are needed.

"So you are in a datacentre, it's 9am and all of a sudden everyone is suddenly hitting that datacentre and they want transactional capabilities, then get them to pull their desktops in from another datacentre elsewhere in the world, where it's just hitting 5pm and everyone is leaving for the day.

"By moving the workloads around in that way you provide the flexibility the business requires."

The private cloud model has the additional benefit of reallocating spare computing and storage power available to organisations to unforeseen peaks in demand; to respond to unexpected demands for processing power in certain regions, for example, or to rapidly provide the IT infrastructure needed to support new business models.

Private cloud technology also makes it possible to...

...minimise the amount of expensive high-performance equipment that a business needs to buy, as it allows organisations to pool their CPUs and storage according to their performance.

In this way tier-one storage - fast access hard disks or solid state drives - can be allocated so it is only used to store data that needs to be retrieved quickly and updated regularly. Tier-three storage, slower spinning and cheaper hard drives, on the other hand can be used for data that's accessed rarely and where performance is not a factor.

Private clouds rely on virtualising servers that are huge distances apart - a process that has historically suffered from the difficulties involved in moving large amounts of data over long-distance networks, typically too slow to provide the real-time access to terabytes of data that enterprises need.

One way around the problem of slow network speeds is to cache the data - storing a copy of the information locally for rapid access - but this poses its own problems, including how to update each of the different caches or copies of that information, so that every person accessing the different caches are seeing and working on the most up-to-date copy of that data.

Vendors - such as EMC, NetApp and IBM - say they are beginning to make strides in overcoming the problems with caching and accessing large amounts of data at distance. EMC recently released a product called Vplex while NetApp has produced FlexCache, which both claim allows different storage arrays to be linked into virtualised central pools of federated storage, providing fast read and write access to data stored in different datacentres.


Datacentres on opposite sides of the world could soon be pooling their computing and storage resources into virtual machines
(Photo credit: Tim Ferguson/silicon.com)

However, Bob Passmore, research VP at analyst Gartner, said while improved caching technology and federated storage will help with migrating virtual machines across long distances, technical challenges will prevent organisations from moving applications and virtual machines across the globe in real-time.

"It will not be instantaneous and the greater the distance, the more performance will be impacted during the time between when the migrated app starts up, and the actual physical migration is complete.

"Is this going to be useful in a number of use cases? Absolutely. Is this going to solve 'federation world hunger'? Absolutely not," he told silicon.com.

As with the industry's favoured truism in the debate around cloud computing versus on-premise software, private cloud proponents believe the technology is not a one-size-fits-all option.

Ted Newman, global practice director of private cloud services for EMC, believes in future companies will...

...draw upon IT services that are delivered from both public clouds - applications hosted on a third party's servers which are shared with other organisations and delivered over the internet - and private clouds composed of their own IT infrastructure.

"As the product and infrastructure continue to improve you are going to be able to choose from your portfolio that is going to include public cloud resources, outsourced resources, internal virtualised cloud and have a balance based on cost and risk," he said.

The public cloud can be more attractive to businesses than the private cloud model when receiving IT services relied upon by large numbers of organisations where governance and security is not the primary concern, as services are delivered from a hosted datacentre, thereby removing the cost of maintaining or purchasing a corporate IT infrastructure.

Other technical obstacles, including limits to the range of hardware that server and storage virtualisation can link together, may mean the private cloud may not be suited to organisations with a highly diverse patchwork of different technologies in their datacentres.

Independent analyst Egge also has his doubts about how wide a market there will be for a global private cloud model, pointing out there are a limited number of organisations with a truly global footprint that would want to shift computing power around the globe.

"That leaves out about 80 per cent of any potential customers because a large proportion of them would not have the demand to match that," he said.

And while tech vendors may be racing towards the private cloud, Egge said, at present, there is considerably less enthusiasm among organisations for the idea of pooling storage and computing power across their entire datacentre estate.

"From my conversations with IT storage professionals there is no desire to do that right now," he said.

"I am not saying that it will not happen eventually but vendors are way ahead of the market right now."

Quocirca's Longbottom added there will always be certain tasks that organisations will want to run from a local datacentre, rather than a global private cloud hub - no matter how far caching technology reduces the delays when accessing data over the network.

"If you are a trading bank the last thing you want to do is cloud. Most trading banks have spent a lot of money in making sure that all connections are as short as they possibly can and as speedy as they possibly can.

"If then you are working from a local datacentre and then suddenly it switches to the Hong Kong datacentre and it introduces an extra half-a-second latency into the trading results coming through, you are losing, probably, millions for every second that that is happening.

"Trying to pull...

...massive amounts of data over the cloud is just too slow because you might have 10Gbps networks internally, while externally most companies will have 2Mbps to 10Mbps level connections. Certain workloads are not cloud-compatible," he said.

Longbottom added businesses may not be willing to spend the time and money dealing with the complexity of managing multiple pools of cached data to allow for long-distance access by multiple users, when services and information could be provided more simply from a local datacentre.

With some tech vendors talking about the private cloud ushering in "new models of computing", Longbottom warned it is important not to get too swept away in promises of what cloud computing is able to deliver.

"We are still at the very early stages of cloud. We are still on the up slope of expectations, so we have a hell of a lot of failures to go through yet and the slough of despondency as people say 'Cloud isn't want we were told it was'," he said.

But while the private cloud model is not suited to delivering every IT service, Longbottom believes organisations will gradually convert large swaths of their IT estates into private cloud platforms.

According to the analyst, the transition is already starting today, with organisations creating pools of virtual servers within individual datacentres to run individual applications.

"Once you have got this clump of virtual servers that is running only one application on, you start thinking 'We have got this excess resource that could be used by other things, so let's start to pull that out'," he said.

"Then all of a sudden these islands of virtualisation in the cloud come together to become one large cumulonimbus.

"By no means do I see this happening in the short term - this is long term - by which time there will be new architectures and new ways of doing things.

"But whatever we call it, cloud computing is the game changer, any organisation that thinks that cloud is just a flash in the pan is not going to be around five years down the line."


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