NSX uses vSphere resource allocation to reserve resources for NSX Edge appliances. You can tune the CPU and memory resources reserved for NSX Edge to ensure optimal use of resources on an NSX Edge.

For maximum performance NSX Edge VM appliance must be assigned 100% of the available resources. If you customize resources allocated to the NSX Edge VM, turn back the allocation later to 100% to get maximum performance.

For auto-deployed NSX Edge appliances, you can change the resource allocation from NSX Manager. However, if an NSX Edge appliance is deployed from vSphere, you can only manage resource reservations for that NSX Edge VM from vSphere.

As per the resource requirements of the Edge VM deployed in your environment, there are two ways to manage reservations:
  • Default values assigned to give 100% resource reservations.

  • Custom values assigned to give 0–100% resource reservations.

Default Reservations

Assumes the NSX Edge set to the High priority. The level of priority importance defines the number of vCPU shares and memory assigned to the NSX Edge. To assign custom values, you can change the relative priority assigned to the NSX Edge.

Resource constraints for different form factors set with Normal priority:

Form Factor Number of vCPUs vCPU Shares (Normal priority) RAM (GB)
Small 2 2000 4
Medium 4 4000 8
Large 8 8000 32
XLarge 16 16000 64
You can tune reservations of an NSX Edge appliance by considering two parameters:

  • Relative priority assigned to a VM

  • Pre-assigned resource constraints for a VM form factor

Custom Reservations

Assign relative priority for an NSX Edge appliance. You can change the relative importance of an NSX Edge appliance to assign the following resource requirements:

For an Extra Large form factor, the releative importance of CPU Reservation Priority, vCPUs and Memory are listed in the following table:
Relative Importance vCPUs CPU Share value Memory (shares per MB configured virtual machine memory)
Extra High 16 34000 64
High 8 32000 32
Normal 4 16000 8
Low 2 8000 4
For example, a High relative importance to an NSX Edge appliance deployed in a medium form factor assigns the following vCPU and memory shares:

  • 4 (vCPUs) X 8000 (vCPU share value) = 32000 shares of vCPU

  • 20 (GB RAM) X 1000 = 20000 shares of memory
Note: Before assigning a CPU value in MHz to guarantee the allocated CPU cycles for an NSX EdgeVM, ensure that the relative importance is set to Low. If the relative importance is set to Normal or High with a custom CPU value in MHz, the VM deployment might face issues due to resource constraints.