Re: [PVE-User] Max limits questions

[Thomas Lamprecht <t.lamprecht@proxmox.com>]

Hi,

Am 16/11/2022 um 07:30 schrieb Anton Shevtsov:
> Where i can find information about below questions
> 
> VM
> 
> 1. Max vCPU count per VM ?

Proxmox VE places no limit on that, so basically how many the PVE host CPU has.
With more the KVM acceleration cannot work any more, so it gets rather slow and unpracticable.
> 
> Node host
> 
> 1. How many maximum CPU cores are supported per node?

Kernel dependent. For the current supported Proxmox VE 7.2's 5.15 kernel it's
8192 per CPU as you can find out by checking the kernel compile config:

grep NR_CPUS /boot/config-5.15.*-pve

Multi-Socket systems normally stop at 4 sockets, but we know a setup with 8 sockets
that uses Proxmox VE. So I guess 8 * 8192 = 65536

> 
> 2. Max RAM are supported per node? (i think - unlimited, but..)

No not unlimited, Linux currently supports 48- and 57-bit virtual addresses.
So, depending on your CPU/Mainboard/... it's something between 2^48 = 256 TiB
and 2^57 = 128 PiB.

In practice the limit will be currently in the range of 6 TiB for modern (last gen)
of Server CPUs. For example, with DDR5 you can get 512 GiB per DIMM and Epyc Genoa
CPUs support 12 channels, so 12 * 512 GiB = 6 TiB.

cheers,
Thomas