The term virtualization is synonymous with being a technology that is easy, cheap and effective, amazingly packaged in one technology. But because many of the normal limitations found in deploying physical servers have been removed, it can get out of control and begin causing its own problems.

VM creation is quick and easy, and because it does not come with the extra hardware baggage, system administrators are more than happy to create new virtual machines whenever needed. But once the job is done, these VMs tend to be ignored and, because they are residing on your physical infrastructure somewhere, they tend to consume essential storage and processing resources leading to VM Sprawl.


Stray VMs, a Bane to Admins

Stray VMs are not something that can be avoided, but the problem gets more complicated as additional VMs are added and the admins shift their attention to the management of these individual systems and away from the overall health of the environment allowing the resources consumed by VM sprawl to get bigger.

All the active VMs tend to be attended to, but the old unused ones previously created, still consume physical and financial resources, and even when powered off, these stray VMs may still have software licensing and support costs attached that can prove to be an organizational burden. Not just that, if the unused VMs are over allocated with memory, storage and processor, then there is a tremendous waste of valuable resources that can be channeled elsewhere. Quickly summarizing, virtualization administrators should keep an eye out for the problems that VM sprawl can cause.

Idle but alive

  • Zombie VMs may seem idle but many may still consume CPU and storage resources, burdening hypervisor performance and wasting expensive storage capacity.

Resource over allocation

  • Because of the ease of creating VMs, admins sometimes end up creating VM’s and over-allocating resources.  By right-sizing these VMs closer to their actual necessary levels, it can be a cost-effective way to free up more memory and storage.

Storage resource crunch

  • Unused VMs occupy storage resources which can be used elsewhere in a virtual environment.  In addition to this, VM snapshots also consume huge storage resources and multiply the VM sprawl impacts.

Software Licenses

  • Along with consuming critical resources, VM sprawl also can use software licenses which may lead to software violation or at a minimum can make it very difficult to get an accurate license count.

Capacity Planning

  • Due to the increased number of stray VMs the administrators may plan future virtual expansion based on the wrong assumptions

VM security tips

VM Sprawl can also represent a significant security risk as VMs that are offline may escape routine security processes. Some of the following best practices can be used as quick tips for effective management of security issues related to VM sprawl security. Have a process to ensure all virtual machines, including those offline, are fully patched and secured on an ongoing basis or at least before they are brought back into the IT environment.

  • Appreciate the architectural differences of a virtual environment including VM sprawl issues and adapt security policies accordingly
  • Apply intrusion detection and antivirus software to all physical and virtual layers
  • Avoid VM sprawl, enforce policies to ensure VM creation is closely monitored and machines are decommissioned after use.
  • Use secure templates for the creation of new VMs


VM Sprawl Control Super Hero


Controlling this situation with the right set of virtualization management tools is essential for the over-worked admins to  put the brakes on virtual machine sprawl by quickly having a handy, affordable and easy-to-use control mechanism that can start governing the pesky situation of VM sprawl quickly and easily can give the admins one less thing to worry about.