Effective selection: beyond the questionnaire

A good questionnaire is a really useful tool for technology selection. It frees the decision makers to focus on the most important parts of the decision.

I have often advised management on technology selection. But recently, instead of being an advisor, I have needed to make the final decisions on technology purchases for my own company. This has given me new insights into the evaluation and decision-making process.

We provide our main product, Metrici Advisor, as a service over the internet. We rent the servers on which it runs. We felt that our existing service provider would not be able to support our future plans, and decided that we needed to move to a new provider.

Perhaps ironically, Metrici Advisor is itself a tool for automating the advice process, so we used Metrici Advisor to structure the evaluation. We developed an evaluation questionnaire, with a weighting and scoring scheme. We created rules for Metrici Advisor's expert system to identify issues with potential providers.

It took us a couple of days to develop a questionnaire that covered all our requirements: connectivity, capacity, scalability, resilience, support arrangements, data centre protection, commercial viability and costs.

We interviewed potential providers by phone. Having a clear set of questions cut through the marketing fog, and we managed to get the answers we needed quickly. Even though the interviews took only 20 minutes, one provider commented that it was the most thorough set of questions they had ever been asked. Metrici Advisor quickly identified which providers could meet our needs and which could not. We ended up with a short list of three providers, all of whom had good scores and no issues.

As we went through the process, our ideas on what we were looking for developed. For example, a couple of the vendors suggested that our needs could best be met by using Xen-based virtualization.

As well as refining our solution, going through the process gave us a much better feel for the providers' technical competence, whether they were the sort of people that we could work with, and how much they wanted our business. These are all vitally important for making the decision, but hard to capture on a questionnaire.

In the end, we selected Goscomb Technologies. They were not the cheapest or the biggest, but we were really impressed by them, and felt that they were the sort of business we could work with very effectively. We have now started to move over to our new servers, and are very happy with the new arrangements.

Using a questionnaire helped a lot. It was a good basis for meaningful discussions with providers, helped us gather information quickly, uncover issues, compare options, and come up with a short list. (And using Metrici Advisor made the process even quicker and more effective, of course.)

But just as importantly, having a good questionnaire freed up our time and attention to focus on the most important parts of the decision. What is the best solution? Which businesses fit with ours? Who do we feel most comfortable with? By combining a formal evaluation process with a less formal exploration of the options, we have made what we believe to be a very good selection decision.

© Copyright 2009 Minimal IT Ltd. See the Minimal IT website for the original newsletter and copyright information.

Virtualization primer 4: recommendations

Always use virtualization unless you have a compelling reason not to, use different virtualization products for different purposes, and expect virtualization products to change.

Server virtualization reduces cost by reducing the number of physical servers that must be bought and run. It reduces risk by allowing different processes to be run separately, reducing the knock-on effect of errors. It provides flexibility by removing the dependency between the operating system and the physical hardware, allowing systems to grow, shrink or move without changing hardware. It helps align technical infrastructure more closely with business needs.

There are three main virtualization approaches.

• Hosted hypervisors such as VMware Workstation allow a guest operating system to run inside another operating system. Hosted hypervisors tend to be easy to set up, and are good for providing test environments or old operating system versions for legacy applications.
• Operating-system level virtualization such as Parallels Virtuozzo and Linux VServer cut a single operating system up into multiple independent operating systems. Operating-system level virtualization provides good performance, and is good for consolidating a large number of similar servers.
• Hosted or bare-metal hypervisors such as VMware ESXi and Xen support virtualization with a layer beneath the operating system. They provide good isolation between guests and predictable performance, and are good for general-purpose production use.

Although it is still developing rapidly, virtualization is valuable, viable and mainstream today. Organisations will benefit from having an effective virtualization policy.

Rather than having a policy which defines when server virtualization should be used, have a policy that assumes virtualization will be used unless requirements dictate otherwise. There are cost, risk and flexibility benefits in most situations. In the rare situations where there are few cost and risk benefits, such as replicated application servers, the flexibility benefits still apply.

If you are using paid-for operating systems such as Windows, consider the licensing implications of virtualization. Linux may be a more cost-effective option for virtualization.

Investigate, select and implement a small number of virtualization products. Different virtualization approaches are good for different needs. Native hypervisors are probably the best approach for general production use where guaranteed performance is important. Hosted hypervisors are useful for testing and special situations. OS-level virtualization is a more specialised approach for consolidating a large number of similar servers.

When selecting products, evaluate them against their intended use, not just ease of implementation. The products that provide the best range of options for production use may be more difficult to implement than simpler products.

It is hard to make specific product recommendations. I suggest:

• Investigate what your hardware and operating system providers offer. All the major technology companies, such as IBM, Microsoft and Sun, have a range of virtualization products.
• Investigate the range of VMware products, as they are a leading independent provider of virtualization technology.
• Investigate Xen.

Expect virtualization technology to change. Over the next few years, virtualization of servers, data storage and networks will mature into a more complete "virtual data center", with added-value activities such as automatic replication, recovery and resizing. This is not a reason to delay use of virtualization today, but a good reason to keep up-to-date with the technology as it matures.

© Copyright 2009 Minimal IT Ltd. See the Minimal IT website for the original newsletter and copyright information.

Virtualization primer 3: example products

There are a large number of virtualization products, with no single dominant vendor.

Last week I outlined the three main approaches to virtualization of servers and PCs: hosted hypervisors, OS-level virtualization, and native hypervisors. This week I will briefly cover some of the best-known examples of each.

VMware is one of the leading virtualization companies, and have been providing virtualization solutions for more than 10 years.

VMware Workstation is a Windows or Linux-based hosted hypervisor. It allows one or more guest operating systems to run on a PC. It can be used for testing, to support legacy applications, or special application requirements. VMware Workstation is a paid-for product, though not particularly expensive.

VMware Fusion is a similar product for Intel-based Macs.

VMWare Server is a free hosted hypervisor for Linux or Windows servers. VMware ESXi is a native hypervisor for larger deployments, and has been released as a free product relatively recently.

VMware Infrastructure is a more complete enterprise-level solution.

Virtuozzo from Parallels is an OS-level virtualization product. This takes a fundamentally different approach to virtualization. Instead of running multiple operating system instances on one physical server, it cuts a single operating system instance into multiple "containers", each one of which then behaves as if it were an independent server. There are Virtuozzo solutions for both Windows and Linux.

Because all the containers share resources, Virtuozzo allows many containers to be packed onto a single server. Parallels claims that it is possible to support thousands of containers on one physical server. Virtuozzo can provide a good environment for consolidating a large number of independent servers onto a small number of physical platforms.

Parallels also provides native hypervisor products and hosted hypervisor products. They support the open source product OpenVz, which is used as the basis for Virtuozzo, but which has more limited features.

Xen is a leading open-source native hypervisor, supported by many large technology companies. Xen is used as the basis of commercial offerings from Citrix, Oracle and Sun.

The Xen hypervisor runs on the physical hardware and runs many separate operating system instances (guests). One of the guests is used to control the virtualization and to provide drivers for the other guests. By separating the drivers from the hypervisor, Xen can support many different virtualization options. It can support both Windows and Linux guests, though Windows is only supported on the more recent Intel and AMD chips that include specific support for virtualization.

Xen is built in to many Linux distributions and can simply be switched on as an option during installation.

This is just a selection of some of the leading products. All the major technology providers, including Microsoft and Sun, have a range of virtualization products, bot free and paid-for. There are many more open-source virtualization products, including emulators (QEMU, Bochs), hosted hypervisors (User Mode Linux), OS-level virtualization (Open VZ, Linux VServer), and native hypervisors (Linux kernel-based virtual machine or KVM).

Each provider supports many different virtualization approaches and options. The products are changing rapidly, borrowing ideas and technology from each other, and often changing ownership. This is a rapidly developing area of technology, with no single dominant vendor.

© Copyright 2009 Minimal IT Ltd. See the Minimal IT website for the original newsletter and copyright information.