Q

Ask the expert: How important is balanced VM resource allocation?

Mistakenly over-allocating or under-allocating VM resources could cost your data center -- both in wasted budget and in compromised performance.

What happens if I allocate an incorrect number of VM resources?

Servers provide only a finite number of CPU cores and cycles and a finite amount of memory space and network bandwidth. Virtualization allows multiple workloads to simultaneously operate on the server. It also organizes and increases resource utilization by allowing one physical server to do more work. It does not, however, create additional VM resources, which causes a resource allocation dilemma for data center administrators.

Over-allocating resources creates unused and ultimately wasted resources. This situation, though not harmful to the server or its workloads, reduces the server's consolidation potential -- the total number of VMs the physical server can support.

Under-allocating resources creates a more serious situation. A lack of resources starves the VM, reducing or even stopping performance entirely. For example, a VM and application with inadequate CPU cycles might run slowly or erratically, and a VM with insufficient memory might rely on disk-based swap files, which could dramatically reduce performance.

Further reading on VM resource allocation

Managing vSphere VM host resources

Common VM provisioning mistakes

The dynamic nature of virtualized resources complicates matters even further. For example, an application may receive more users over time, which would increase its network bandwidth demands beyond the original allocation. Application upgrades may also incur additional CPU or memory demands. It's important to monitor resource use and application performance on an ongoing basis and adjust resources as necessary.

This was first published in May 2013

Dig deeper on Server consolidation and improved resource utilization

Pro+

Features

Enjoy the benefits of Pro+ membership, learn more and join.

Have a question for an expert?

Please add a title for your question

Get answers from a TechTarget expert on whatever's puzzling you.

You will be able to add details on the next page.

1 comment

Oldest 

Forgot Password?

No problem! Submit your e-mail address below. We'll send you an email containing your password.

Your password has been sent to:

SearchVMware

SearchWindowsServer

SearchCloudComputing

SearchVirtualDesktop

SearchDataCenter

Close