Management vs. the virtual server

A look at how the industry is moving to abstraction

By Austin Modine in San Francisco • Get more from this author

Posted in Servers, 9th August 2007 00:30 GMT

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Mysterious savings

The jury is still out on the impact of virtualization upon operating costs. There's the intuitive benefit of reducing time of server deployment, but this is a bit tricky to quantify. Sure, creating a virtual server avoids having to spec out the system, buy the hardware, wait for it to be shipped, install, bring it up, etc. - and that's valuable from a manager's standpoint. But you aren't saving money per se.

Ideas International found that many users were performing internal total cost of operation studies, but none are yet complete. Some are doing the the research, but nobody was willing to give out metrics just yet.

Virtual choices

Businesses were drawn to VMWare primarily for VMotion. Customers either routinely used VMotion for production workloads, or had a strong interest in using it in the future.

Iams said he was surprised by how often Ideas ran across businesses running Microsoft Virtual Server, and also how many were pleased with it. The research firm found that while often businesses were turned off by the heavyweight Windows OS host and lack of manageability, they also found the software matched the maturity of the organization. Many weren't yet ready to use the advanced features of more robust virtual software such as VMWare, but expect Microsoft to fill in the holes later - which is when the business would take the plunge as well. Iams noted the faith of many respondents in the interoperability of virtualization software. The consensus was that if Microsoft doesn't eventually deliver, they will be able to switch between virtual disk files.

Ideas found customers were generally hesitant about implementing XenSource. Overall, there were concerns about the requirements for customized kernel and lack of commercial support. The stigma of open source is still a hurtle for Xen to overcome as well. Companies remain reluctant to implement software when they don't see a company behind to hold accountable.

Management impact

On the x86 platform, Ideas found that virtualization made it much easier to deploy new systems. But this comes at a cost. The ease of creating virtual servers increases the demand for them. Suddenly, there are more servers to manage than ever before. From a manageability standpoint, going virtual is not all that different than physical, but the burden can actually become worse.

Ideas found less complaints on the Unix side. Managers typically treat virtual servers the same as physical servers and continue to use the same tools.

Recommendations

Iams parted with recommendations for company's considering consolidation.

Know your apps. Be sure to classify the suitability of workloads for virtualization by measuring performance characteristics over time and understanding their dependency on different resources (CPU, memory, I/O.)
Choose the appropriate virtualization platform. I/O-heavy applications will take a hit on x86 platforms, so for critical workloads, you should consider Unix or mainframes for today.
Evaluate different virtualization approaches and products. Don't set your heart on one product before checking out VMWare, MS Virtual Server, Xen, SWsoft, Viruozzo, etc.
Adapt management procedures and tools for virtualization. Focus on managing the relationship and dependencies between virtual resources and their physical counterparts. Large levels of consolidation need much better tools to manage virtual servers.
Maintain modularity between tools for managing physical server resources, virtual server resources, and storage resources. Don't get bogged down into having one over-arching framework controlling everything passing information between levels. ®