A common question I get with CapacityIQ is why some VMs appear in both Oversized and Undersized Virtual Machines List views. How’s that possible? Are the VMs oversized or undersized?
This is possible for several reasons:
- Remember that CapacityIQ 1.0.x uses both CPU and Memory metrics to analyze oversized
and undersized VMs. It’s quite possible that a VM is oversized for one
metric and undersized for other. If so, it will show up on both lists.
- Also note that this analysis is done over a time period (that can be
configured from CapacityIQ Global Settings). A VM running varying workload during
this time period can show up in both possible lists.
- The Capacity Buffer limits also affect the oversized and undersized VM analysis. The capacity you set aside as reserve or buffer is taken into account when generating these views. You may want to play around with the Capacity Buffer values in CapacityIQ Global Settings to see how it impacts these oversized and undersized VMs lists.
To find out what’s
really going on, you can select the specific VM in the left side inventory and look at
the Virtual Machine Capacity Usage -Summary View. The screenshot below provides an example. You will notice that the same VM is undersized in terms of CPU capacity, but oversized for memory.