[SOLVED] How to share the CPU ?

[infogram]

Hi there,

First of all, thanks for that great software. I mean, I'm just starting using it but I'm pretty confident it's gonna suit me fine.
Also, apologies if my question has already been asked before. It's a beginner's question (cause I'm a newbie) but I haven't found the answer in the forum.

Here is my situation :
My host server is Debian 7 (because the server's management software doesn't run on debian 8). PVE version is : proxmox-ve-2.6.32: 3.1-114 (running kernel: 2.6.32-26-pve)
I'm willing to create 3 KVM guests. My question is : How do I share the CPU ?
The host has 2 Xeon processors (E5-2420) Each one is 6 cores / 12 threads
In the host summary, PVE reads : 24 x Intel Xeon CPU E5-2420 v2 @2.0 GHz (2 sockets)
(So 24 is the number of threads, but I only have 12 cores)
When I create a guest, on the CPU step, I'm asked about the number of sockets & the number of cores.
And the total for the guest will be (sockets x cores)
Let's say I'm gonna give 3 cores to each of my guests (and 3 left for the host)
My idea is to leave the socket number to 1 for each guest and just change the core number to 3.
Am I right about this please ?
(The thing is I don't understand why I have to deal with the socket number here. Because I feel managing the number of cores would be enough. But obviously, I'm missing something)

 

[wolfgang]

Hi,

Yes you thoughts were correct.

The socket is only useful, if you want to give the vm the awareness of numa.
In your case it would be necessary if one vm has more then 12 cores.

When you use kvm vcores are processes.
So the kernel takes care where the process runs.

This makes it also possible to have total(all VM's) more vcores then real cores/threads.

 

[infogram]

Thanks, Wolfgang, for the quick reply !