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Five rules to ease VM provisioning

Incorrectly sizing a VM can lead to poor performance or wasted resources. Implementing a formal VM provisioning process and taking these five rules can help mitigate the risks.

It's not that application and server administrators set out to abuse the system and intentionally overprovision VMs. Instead, they want to provide the best possible experience for end users. Oftentimes this means following vendor guidelines for installing applications. Those recommendations, though, are nothing more than guidelines or minimums to help the VM provisioning process.

Yes, it is possible to install Windows Server 2012 with 512 MB of memory; it's the minimal recommended specification. The likelihood, however, that it will function to any level beyond simply logging in is remote at best. IT professionals tend to fall into one of two camps with regard to posted specifications and server configurations:

  • The ones who follow the vendor to a fault. Vendors can give a recommendation based only on what they have seen in other environments. They extrapolate from different environments and give you an estimate of what you'll need. This estimate might be close, but it cannot be exact. Each environment simply has too many specific needs and configurations of its own.
  • The ones who double what the vendor says. Seasoned IT professionals know from experience that vendors tend to recommend specifications that are low (to ensure that the sale goes through without worries about hardware needs). Knowing this, IT teams will often overestimate the resources needed. In many cases this can result in hardware running at minimal usage.

IT administrators can end up in a tough spot trying to balance estimated needs with actual needs. Keep in mind, though, that with virtualization it is easy to grow. Start slow and -- through careful monitoring --grow your virtual machines in size and quantity.

When examining application usage and growth, a common mistake is to design for either the minimum or the maximum. Applications and users are not static values, however. They grow and change depending on the business. The infrastructure used to support them needs that same elasticity.

Tips to improve VM provisioning

With everything in the applications and infrastructure being so flexible, it's wise to establish VM provisioning rules to help work with this flexibility while still maintaining control. Here are some guiding points to keep in mind:

  1. Don't leave your virtual machines 100% open-ended. Given an unlimited set of choices for CPU, memory and storage, people will ask for -- and expect -- the moon. Create tiers of VMs in which 90% of your requests will fit. Having the tiers will help to make people stop and examine the options rather than simply guessing at hardware values. Start by creating light, medium and heavy virtual server categories. Still, retain some flexibility to adjust these. This gives users common starting points without sacrificing the flexibility that virtualization provides.
  2. Establish a length of deployment. Setting a guideline for how long a VM will be deployed reinforces the idea that it may not be available forever. Create preset windows for test and development uses and a permanent level for production uses.
  3. Use a request form/workflow. Virtual infrastructure is not something to be divvied out in conversation at the water cooler. Putting in place an organized request process for VMs will help contain VM sprawl and deter frivolous requests. An online form is an ideal way to create a streamlined process so that requests can be handled in as few steps as possible. Keep in mind that the longer and more complex the form, the less likely people are to complete it.
  4. Use a smart authorization process. While a new virtual machine needs some level of authorization, not everything needs the top manager's signature. Allowing some flexibility with approvals will help to streamline the process. Let team leads give the go-ahead for test and development servers with limited deployments, but require department managers to approve full production requests. This keeps the process moving, while ensuring that management signs off on higher-resource, long-term VMs.
  5. Allow exceptions to the rules but not without an additional process. We have all heard the request for "just a few more days." While there is nothing wrong with granting an extension, be sure that such a request is subject to the same approval process. This aids capacity planning. It also establishes in people's minds that a virtualization management process is in place for a reason and that it needs to be followed. Providing users with a consistent, known process is essential to establishing guidelines that everyone can adhere to and understand.

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