When monitoring a virtualized environment, it’s important to understand the various performance issues & bottlenecks that may arise. As most virtual admins know, VM sprawl doesn’t occur over night, rather over a period of time and for a number of reasons.
For example, as a Virtual Admin, create VM’s based off of demand and can do so very easily, especially since new hardware isn’t required. When the number of VM’s increases within your infrastructure, it can lead to a lack of resources, performance issues, bottlenecks, or worse…VM sprawl.
The key to address these issues is to focus on resource utilization because if not properly allocated, ROI can even be affected. Provided below are a few areas virtual admins can focus on to better utilize their resources and avoid VM sprawl:
Zombie & Idle VMsare allocated a certain amount of resources, however with them being idle, these resources aren’t being utilized. In turn, other VM’s are affected due to their lack of resources. Signs of zombie & idle VMs:
– No recent login by users. For example, when employees leave an organization, their VM will become idle
– No recent file modification, as users aren’t using the VM
– Check when last powered on or off
By eliminating these VMs you can reclaim the wasted resources.
Rouge VMs are allocated a share of resources, yet they continue to consume additional resources. In turn, these VMs grow faster than they’re supposed to. Rogue VMs are one of the major causes for latency. You should drill down further to understand why these VMs grow at such a rapid rate. By checking their historical data & you can determine the reason for these changes and remediate accordingly.
Over allocated VMsconsume a lot of resources that aren’t needed by the end-user or client. It’s recommended to right size all your VMs. Look out for VMs which have under utilized CPU, memory, and storage. Analyze their historical consumption to understand the cause for over allocation in a VM and if it will be permanent.
VM Sprawl doesn’t happen overnight and it is not easily noticeable. VM Sprawl becomes a performance issue and bottleneck over a period of time. Some recommended solutions to overcome performance issues from VM sprawl:
– Don’t allocate too much memory and other resources. Go through with software or an application manual, assign resources per the recommendations given by the vendor.
– Allocate single vCPU at first, add more later on if needed.
– Monitor & delete VMs that are no longer needed to reclaim wasted resources.
– Don’t create snapshot of each VM. It is recommended to archive VMs so you can save storage space.
– Keep a historical log of configuration changes to track what changed the performance graph.
– Chargeback or showback to understand the cost of each VM.
– Check with business groups to understand the need for creating a VM.
– Define rules for maximum number of VMs allocated to an individual/user/department.
By utilizing these few tips on resource utilization you will be able to avoid VM sprawl. While these tips are useful, it is recommended to implement a modern virtualization management tool to make it easier to identify & control VM sprawl. You will be able to monitor and account for all resources being used. In turn, you will be eliminate bottlenecks in VMs.