Capacity planning involves figuring out what happens when you add servers and other resources to the cluster as needed to keep up with business demand. Capacity planning is a major component of the cluster and the cloud's performance. If it's done wrong, you might end up with useless systems or have to shoehorn-in traditional, noncloud systems to keep things running.
Most organizations aren't good at monitoring and keeping ahead of capacity. To be able to satisfy user demands, you always need to have some extra capacity on the data center floor, which results in a certain amount of hardware sitting around in idle mode. Keeping a history of capacity usage in your enterprise can help you be reasonably confident that you have sufficient -- but not too much -- capacity.
One solution is to create a hybrid cloud environment and move requests for capacity to public clouds, such as Amazon.com Inc.'s Elastic Compute Cloud, when capacity isn't available in the private cloud.
Once the cluster is up and running, you can start provisioning virtual servers. The result is a tiered architecture with a server layer, a network layer and a virtualization layer. There is a management tool at each layer. "Now you can start thinking about automation," Driscoll says.
In Perspective: Storm Clouds On the Horizon
Building your own private cloud involves some challenges, including the following:
* Budget. Private clouds can be expensive, so figure out the upper and lower bounds for your return on investment.
* Integration with public clouds. Build your private cloud so you can move to a hybrid model if you need public cloud services. This will involve making sure systems are secure and verifying that you can run your workloads in both places, among other things.
* Scale. Private clouds usually don't have the economies of scale that large public-cloud providers provide.
* On-the-fly reconfigurations. You may have to tear down servers and other infrastructure -- while it's still in use -- to move it into the private cloud. This could create huge problems.
* Legacy hardware. Leave your oldest servers behind. Don't try to repurpose any servers that require manual configuration with a private cloud, because it would be impossible to apply automation and orchestration management to these older machines.
* Technology obsolescence. The complexity and speed of technology change will be hard for any IT organization to handle, especially smaller ones. Once you make an investment in a private cloud, you need to protect that investment by staying up to date with new releases of software components.
* Fear of change. Your IT team may not be familiar with private clouds, and there will be a learning curve. You may need to create some new operational processes and rework some old ones. Turn this stressful situation into a growth opportunity for your staff, reminding them that these are important new skills in today's business environment.
You'll need to acquire management tools that can bridge the physical infrastructure and the virtual infrastructure. So choose tools that let you see the same view across execution environments.
One layer of management is the infrastructure, which includes managing virtual machines, storage, backup/recovery and so on. While vendors often claim that their products are targeted at private cloud infrastructures, they sometimes use a very loose definition of "cloud," so carefully investigate the functions of each product.
The second layer, service-level management, involves managing workloads at a level of abstraction above virtual servers. This is where automation is applied. It is also where traditional management tools such as IBM's Tivoli and Hewlett-Packard Co.'s Insight work within the private-cloud stack. Vendors that claim to have automation management tools include IBM Tivoli, HP, CA, LineSider Technologies, DynamicOps, VMware and BMC.
Iams says that almost all system and hardware vendors are pursuing some type of virtualization or cloud management tools. Microsoft's System Center management product, for example, offers visibility into hypervisors and virtual servers.
But Iams says you should plan on managing multiple hypervisors, such as VMware's ESX, Microsoft's Hyper-V, the open-source Xen, and various implementations of the Linux KVM (Kernel-based Virtual Machine). Microsoft can manage Hyper-V virtual servers and some aspects of ESX virtual servers. Other cloud vendors, such as VMware and Red Hat Inc., can also manage virtual machines created by multiple hypervisors. Ideally, you want to control multiple hypervisors from a single interface.
Buy or Build?
The downside of commercial, off-the-shelf tools is that they will likely need to be customized to work with your environment. On the other hand, the downside of rolling your own tools is that your in-house IT group will need to maintain them and make feature enhancements. One alternative to homegrown tools is building mixed-component cloud stacks by acquiring various third-party components and putting them together. The question then becomes: Who do you call when there's a problem?
You could choose to go with a single provider, such as Microsoft or VMware, but that can result in vendor lock-in.
Open-source software -- from the OpenStack project and from vendors such as Abiquo, Cloud.com, Eucalyptus Systems and Red Hat -- is a good choice for building private clouds. The software is essentially free and provides more flexibility than proprietary software licensed on physical CPUs. For example, proprietary software can create difficult licensing issues when migrating virtual machines from host to host.
Each alternative has its pluses and minuses, so weigh your options carefully, because switching gears once you're already under way is expensive and time-consuming. Don't lock yourself into a single vendor's cloud stack. In particular, avoid vendors with cloud stacks that perform well when using only their components. Reserve the option to plug in third-party or homegrown tools.
Here's a sampling of vendors that claim to have tools for building private clouds.
* BMC Software Inc. (Cloud Lifecycle Management)
* CA Inc. (3Tera AppLogic)
* Cisco/EMC/VMware (Vblock)
* Citrix Systems Inc. (Citrix Open Cloud)
* Cloud.com Inc. (CloudStack 2.0)
* Dell Inc. (Virtual Integrated System)
* Enomaly Inc. (Elastic Computing Platform)
* Eucalyptus Systems Inc. (Eucalyptus 2.0)
* Hewlett-Packard Co. (BladeSystem Matrix)
* IBM (CloudBurst)
* NewScale Inc. (NewScale 9)
* Platform Computing Corp. (Platform ISF)
* Tibco Software Inc. (Tibco Silver)
* VMware (vCloud)
Source: Forrester Research Inc., August 2010
So far, it isn't possible to buy one commercial product that will do everything IT managers need to do for private clouds. You have to stitch together a number of different products from various vendors and place your own user interface on the front end.
But Verizon Business' Deacon says that more-sophisticated enterprises are integrating multiple management tool sets -- for instance, HP's Server Automation suite and BMC's Patrol suite. Security, firewall, networking and storage elements can be orchestrated from within both HP and BMC suites. IT shops that don't link multiple tool sets may have to write a lot of their own software to get the necessary automation capabilities.
Is single-console management a real possibility for private clouds? Not everyone will be able to get by with just one console, says Iams, but even two or three consoles would be a huge improvement over the dozen that some shops use today.
Deacon says that single-console management is in the cards, noting that Verizon Business has built a high-level console management layer that collects data from VMware vCenter Server, HP Network Automation and HP Virtual Connect, among other products.
Vendors Will Consolidate
Frank Gillett, an analyst at Forrester Research Inc., isn't so optimistic. "It is unrealistic to think that we are going to get many of these management tools to work together," he says. Instead, he predicts that over time, the market will shrink dramatically through acquisitions, leaving a handful of vendors that will offer "much more integrated capabilities." And some IT managers prefer large, established vendors for cloud technology because they can't trust their data centers to start-ups that may not be in business in a year or two.
Deacon agrees that consolidation is likely as large companies like HP and IBM buy up cloud-based start-ups and add the new software to their existing portfolios. That's what HP did with its acquisition of OpsWare. Similarly, BMC absorbed BladeLogic, and CA has been on a buying spree, acquiring Nimsoft, Oblicore, 3Tera and others.
IT shops need federation and interoperability, Gillett adds, "and we are very early in those efforts. We may be able to bring private cloud management tools together, but it will be a messy interim period."
Yet during that period, IT shops will be under enormous pressure from business users to engage in cloud computing. If the data center operations group can't respond quickly with a private cloud, then business users will look at public clouds. To successfully compete with public cloud providers, IT departments will need to deploy similar services in-house, and those private clouds will have to be better and more attractive to use than public clouds.
Claybrook, an analyst with more than 30 years of experience in the computer industry, is president of New River Marketing Research in Concord, Mass. Contact him at firstname.lastname@example.org.
This version of this story was originally published in Computerworld's print edition. It was adapted from Part 1 and Part 2 of a feature that appeared earlier on Computerworld.com.
This story, "The bumpy road to private clouds" was originally published by Computerworld.