vCores

[manfer]

I have a server with 2 sockets with Xeon E5620. This CPUs are 4 cores 8 threads.

On the proxmox dashboard the CPU info reads: "16 x Intel(R) Xeon(R) CPU E5620 @ 2.40GHz (2 Sockets)"

¿Which is the maximum vCores to uses on a VM? ¿2 sockets 4 cores or 2 sockets 8 cores? And, ¿can I shared cores in several vitual machines? ¿can I use the maximum on 2 different VMs?

 

[Dunuin]

I have a server with 2 sockets with Xeon E5620. This CPUs are 4 cores 8 threads.

On the proxmox dashboard the CPU info reads: "16 x Intel(R) Xeon(R) CPU E5620 @ 2.40GHz (2 Sockets)"

¿Which is the maximum vCores to uses on a VM?

You need atleat 1 core to be unused by a VM so the VM can't block the hosts processes. I wouldn't assign more than 14 vcores to a VM.

¿2 sockets 4 cores or 2 sockets 8 cores?

2 sockets 8 cores but keep in mind that threads only got a fraction of the computation power of a real core.

And, ¿can I shared cores in several vitual machines

Yes, no problem to create for example 10 VMs with 4 cores each with your CPU as long as the VMs are idleing most of the time.

¿can I use the maximum on 2 different VMs?

Yes.

 

[manfer]

You need atleat 1 core to be unused by a VM so the VM can't block the hosts processes. I wouldn't assign more than 14 vcores to a VM.

I just have one doubt now. So if I use 14 vcores in one VM and again 14 vcores in another VM, that would not block host processes?

Thanks.

 

[Dunuin]

I just have one doubt now. So if I use 14 vcores in one VM and again 14 vcores in another VM, that would not block host processes?

Thanks.

It could, but you can always run into this problem when using overprovisioning. Only option is to never overprovision or to pin your KVMs threads to specific cores, so no VM is able to use a specific core.