Seven Truths about virtualization

Virtualization is a revolution for data centers, but there is no such thing as a potential flaw or even a trap. Problems with management, security, ROI, and energy utilization can cause errors in virtualized deployments.

"Virtualization is likely to bring great cost savings and technical advantages," said Laura DiDio, chief analyst at Information Technology information consultancy, who believes that the cost of space and energy requirements can be greatly reduced through server consolidation, "However, these cost savings are not automatically generated." ”

She cites 7 big questions-let's call it a half-truths statement, which should be fully considered by the enterprise before implementing the virtualization project.

Will virtualization make management easier?

Server virtualization greatly reduces the time to add new workloads. Some enterprise IT departments report that they can deploy a new virtual machine (VM) in less than 30 minutes, while deploying a similar physical machine takes several weeks. It seems that virtualization can simplify the promise of it in many ways is true.

But virtualization also introduces new management challenges that cannot be ignored. IT departments need to develop stringent policies and perhaps third-party automated tools to prevent the virtual server from clutter and the VM's unrestricted spread. Burton Group analyst Chris Wolf says that while the number of physical servers is limited, the number of objects to be managed has increased significantly in general, as there are a large number of hypervisor and VMS.

Many users assume that the time spent on management will be shortened, but the virtual infrastructure itself needs to be managed and may even need to build a new centralized storage system, said Martijn Lohmeijer, a management consultant for IT outsourcing and consulting firm Trinext.

What is even more frustrating is that many software vendors are far less able to support applications running on VMS than for applications running on physical servers. Microsoft last year eased certain licensing restrictions on support for virtualized environments, but analysts remain critical of the restrictions on Oracle and other software makers. In virtual data center, the calculation formula of software license fee is more complicated.

"Not all server virtualization licenses are the same," DiDio said. "You must carefully study all the terms and conditions of the license agreement that you and the different manufacturers have signed," he said. ”

Is it necessarily simpler to consolidate into fewer servers?

The primary purpose of server virtualization is often consolidation. If you can run the workload on the original 100 servers on 10 servers, why not implement the integration as soon as possible? Unfortunately, many IT departments have found in the process of implementing the consolidation plan that the integration steps are much more difficult than they had expected. "A virtual machine runs a new workload," says George Pradel, a Vizioncore managing director of virtualization management, but moving old workloads from physical to virtual machines is not always a simple task, he said.

"There are a lot of unexpected things going on when you do p-to-v or physical machines migrate to virtual machines," Pradel said. Because this migration "is not carried out in a vacuum." This migration involves the work arrangements of different business units, and they must have the mental preparation to withstand considerable downtime. ”

Will virtualization automatically reduce energy consumption?

If you reduce the number of physical servers by consolidating, you may be excited to say, "I've solved the problem of energy consumption." "But the situation is not so simple. Although the number of servers consuming energy is low, the CPU utilization of each server is greatly increased and therefore requires high power consumption. John Turner, head of network and systems at Branders University in Massachusetts, reported that one of the school's virtualization projects actually increased the overall power consumption. Branders Although the number of physical servers has been greatly reduced, and because more VMS have been added to provide more services to users, but each new workload or virtual machine uses more power.

"If you go to the back of these virtual server racks, you'll find the heat from these guys really scary," Turner said. "We're pouring heat into the data center that we've never had before," he said. ”

There is also a question to consider: If you turn off a lot of physical servers, the data center will have to be reset to stop the air conditioner from being discharged to a place that doesn't need air-conditioning, says Jim Simoneli, an APC CTO.

"When virtualization becomes more and more important, it takes a holistic look at the reconfiguration of the power and cooling systems," he said. "If you just do virtualization without considering changing the data center infrastructure, then virtualization can be less efficient than you might expect." ”

Is virtualization safer?

The ability to clone a VM and migrate it from one physical server to another opens the door to disaster recovery. However, if virtualization is poorly managed, it can also create new security risks that threaten the security and stability of data and business system continuity.

Joshua Corman, an IBM security expert, believes that it is often the case that people and processes in an enterprise are not usually prepared for virtualization and the security risks it poses.

Virtualization introduces a new attack interface, as well as various operational risks. Putting a lot of applications on a single server "gives the enterprise a singular point of failure," DiDio points out.

If the virtual server is cluttered, it can be difficult to track all the VMS, and it's hard to make sure that all the VMS are patched in time. In addition, hypervisor is not encrypted and can open the door to man-in-the-middle attacks such as xensploit.

Can desktop virtualization really save money?

Virtualization makes it easier to deploy new desktops, update patches, and perform other administrative tasks. In the long run, desktop virtualization can also save money. Denver is expected to receive a 619,000 dollar return on investment over the next 8 years by buying thin clients that live longer than traditional PCs.

But it must keep in mind that desktop virtualization requires significant upfront costs, such as the need to buy front-end devices such as thin clients, and the back-end facilities that support VMs, such as servers, blades, and networked storage.

Interestingly, Forrester analysts have found that in order for the virtualization project to be launched and put into use in the first year, the company's spending is 860 dollars per user, which is not counted as a network upgrade. A well planned desktop virtualization project will certainly save costs in the long run. But there is no return on investment in the short term.

Is virtualization like cloud computing?

Virtualization is the key to the possibility of cloud computing. But installing VMware on a handful of servers doesn't mean you're building a private cloud. In addition to virtualization, private cloud requires a service automation technology and a self service Interface for preset new resources, said Kristof Kloeckner, IBM's cloud software director.

In a blog post titled "Virtualization is not cloud computing," Reuven Cohen, founder of Emerging Enterprise Enomaly, believes that virtualization is just building materials for cloud computing, and the real key is the abstraction of each layer of it stack.

Clouds do not necessarily need virtualization. This is confirmed by Google officials, who say they do not have virtualized production hardware, but instead use a task scheduler designed by Google to manage thousands of of servers.

Is virtualization always about technology?

This problem is not a problem for senior it people because they know that in order to implement a project, sometimes the key is people rather than technology. As Corman says, people and business processes are often not prepared for the new challenges that virtualization poses.

Even if your virtualization project succeeds, you may be the victim of your own credit. Once users realize how easy it is for them to add a VM, they are likely to ask for more, making it impossible for the IT department to focus on other tasks. On the contrary, resistance may also come from users who have become accustomed to using physical servers.

Pradel This human-related strategy as the "eighth floor" of the network layer, also called the political layer.

"The political layer is the hardest thing to deal with when you're dealing with virtualization projects," Pradel said. "In your business there will certainly be a group of people I call dead holding the server." They don't want to give up on the physical servers they've used, even if they benefit from virtualization. ”