CPU & Memory Reservation

[rajeevsrikant]

In the NSX 6.3.2 release notes its mentioned about the CPU & Memory reservations for the NSX Edge gateway.

Would like to know is it necessary to do the CPU & Memory reservations during the upgrade process.

If the hosts where the Edge Gateway resides have sufficient CPU & Memory resources is it required to set the CPU & Memory reservations ?

VMware NSX for vSphere 6.3.2 Release Notes

[senthilkumarms8]

Staring from NSX 6.2.5, When you deploy ESG and DLR VMs by default the CPU and memory reservation will be configured with 100%. since ESG is one of the very critical components for SDDC environment.

it requires enough CPU/Memory resources to function properly. Irrespective of available host/cluster resource.

The screen what you referring is the upgrade notes. before the upgrade, you should make sure that host has enough resource and it is not violating any HA admission control policy.

if any such issues then upgrade might fail. Because during the upgrade NSX manager will re-deploy the ESG VMs with 100% reservation. so to avoid such failures it is better to configure the reservation before the upgrade process.

[rajeevsrikant]

I am upgrading from version 6.2.2 -> 6.3.2

So if the ESXi hosts has sufficient CPU & Memory resources should i need to consider reservation.

If I have sufficient resources, i feel i don't need to do any reservation.

Let me know if my understanding is right.

[senthilkumarms8]

you should consider the reservation. it doesn't matter whether you have sufficient resources or not.

may I know what are we trying to achieve without reservation?

[rajeevsrikant]

ok got it

for reservation my understanding is that it is possible only via REST API

Let me know if my understanding is right.

Also let me know how much CPU & Memory reservation i need to keep & what is the REST API command for it.

[rajeevsrikant]

The below article says that by default the below reservations are used.

So I want to specify the reservations , how much should i keep.

[senthilkumarms8]

100% CPU and memory reservation is required for each ESG Vm. The Rest API is there in your screenshot

1. PUT https://<NSXManager>/api/4.0/edgePublish/tuningConfiguration
   ensuring that values for edgeVCpuReservationPercentage and edgeMemoryReservationPercentage fit within available resources for the form factor (see table below for defaults).

The following resource reservations are used by the NSX Manager if you have not explicitly set values at the time of install or upgrade.

NSX Edge Form Factor	CPU Reservation	Memory Reservation
COMPACT	1000MHz	512 MB
LARGE	2000MHz	1024 MB
QUADLARGE	4000MHz	2048 MB
X-LARGE	6000MHz	8192 MB

[grosas]

Edge Gateway CPU/MEM reservations were introduced in 6.2.3.

With 6.2.5 onwards - 100% reservations are used at deployment. 

Assuming your edges are in the network path for your workload, you do want to ensure this component always has reserved access to resources during contention (as your virtual machine volume grows).