I am the new girl

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Minus planning, the technology can invite a lot of problems.

Many of us understand the nuances of server virtualization —you take a server, you replicate it into a hosted environment using some sort of Virtual Machine Software and then you retire the physical machine from its former purpose. Sounds simple, and for the most part it is. Software products like VMware have made the process very simple and have made virtual server utilisation a very commonplace event. But, in the mad rush to virtualise everything there has to be an
evaluation of what to virtualise.

Everything is beautiful
I recently attended a conference where virtualization was the hot topic. One

CTO even boasted about how many physical servers he had retired — it was impressive. But, when I asked him what his effective throughput rate or transaction was with the new virtual environment as opposed to his physical server infrastructure he had no answer. It is not an uncommon occurrence. Many top IT professionals don't look at their metrics before they do something, and then have no idea how they have helped, or hurt, themselves.

The obvious positives of virtualization are clear — lower power consumption, simpler server duplication/replication, easier server management, simpler IP address and VLAN management, etc. The Aberdeen Group conducted a study in 2008 which outlines some of these issues. In it, they found that organisations experienced 18 percent reductions in infrastructure cost and 15 percent savings in utility cost by virtualising their server environments.

Honey, I shrunk the server!
So, this CTO took his server environment from 180+ servers to fewer than 60. What did he virtualise? In his own words, "everything." I followed up with him on the details and they have indeed virtualised everything. But after our meeting at the conference he began to think more on what we had discussed about performance and throughput. Since he had no metrics prior to virtualising he had to use a more ad hoc method — user feedback. This is often very problematic unless you have vetted the responses objectively.

To his chagrin, he noticed that trouble tickets related to his BES (blackberry enterprise server) had risen by 25% in the 30 days since that environment was virtualised. A huge rise given his company has more than 1300 Blackberry users. If only his people had done their homework ahead of time they would have realised, based on other companies experiences, that BES can be virtualised, but there can be some sever IO penalties and performance can (and most often does) suffer.

To P2V or not to P2V: That is the question?
E-commerce systems were some of the frst to be virtualised because of their, typically, web based components. Web servers, typically, do very well in a virtualised environment. Some will argue that virtualization was made for web servers and internet application servers. But is this a global truth? There is a great deal of evidence that virtualization can muddy the waters when it comes to performance.

A key challenge for organisations adopting virtualisation is effectively managing application performance in virtualised environments. The capabilities required in a virtual environment were not necessary when these organisations were looking to achieve the same performance goals in physical environments.



Full speed ahead..
One of the biggest uses of virtualization is server consolidation. Many larger companies had, for the longest time, multiple data centres that interacted and interfaced continually (or using batch processing). Users in each location logged onto their local servers which then exchanged data between sister servers in other locations. WAN traffc was, thus, consolidated and data greatly compressed.

With virtualization, many companies have opted for more centralised computing environments. So, users in Europe now have to log on to servers in the US, whereas before they logged onto servers locally. WAN traffic then starts to increase and system bottlenecks become more common. These are not abstract observations or "what-if's." They are real life occurrences that companies have experienced. Because of the increased WAN traffc, the end user experience, for internal and external users, was not improved and actually degraded.

Thus moral to this story is — PRIOR PLANNING PREVENTS POTENTIALLY POOR PERFORMANCE.

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