Dedicating vCPU cores

[pan1268]

Hello Experts,

Need an advice on to how to dedicate the CPU cores to a VM. Actually, my requirement is something like this :

I am having - ESXI hosts with 2 sockets * 18 cores = 36 cores in total ( assuming will not enable hyperthreading ) ( Intel processor with 2.6 GHz)

Now would like to deploy 2 types of VM :

1_ 1 Virtual Machines of 24 core (it is must to have 1:1 cpu core ratio meaning no oversubscription is allowed)

2_2 Virtual Machine of 10 cores each  (  can have 2:1 cpu core oversubscription for these VMs )

Now, the total cores I have on ESXI hosts is 36 and therefore this is how I am planning :

36 cores = 24 cores ( from 1 VM with 1:1 cpu core ratio ) + 10 cores ( from 2 VM where 2:1 cpu core oversubscription is possible ) + 2 cores for running ESXI 6.5 host.

Experts could you please guide me if this is the right plan and division of cores . If this is the right planning could you please guide me how will ensure that 1 VM will get 24 cpu cores exactly.

[depping · Accepted solution]

What is the use case for this? You could potentially pin a VM to specific cores, but I would avoid this at all costs. Simply specify the number of vCPUs you require and let vSphere take care of the scheduling. As soon as you start pinning you limit scheduling possibilities and typically it will not get better in terms of performance. So just deploy the VMs and see how it goes. I would also recommend considering lowering the number of vCPUs per VM, do they really require 24?