Dear yuanle,

Thank you for the information. You might be right.

But I am still confused about what’s the difference between a vCPU and a physical core.

Regards,

Cheng

From: sylecn [mailto:sylecn@gmail.com]
Sent: 2014年3月17日 15:06
To: WANG Cheng D
Cc: libvirt-users@redhat.com
Subject: Re: [libvirt-users] a question on vCPU setting for lxc

Hi,

I'm not libvirt expect. My guess is that some vcpu settings only apply to KVM/qemu backend. LXC is quite different from them.

If setting vcpu# is not effective for LXC container, you may need to use cgroups.

--
Thanks,

Yuanle

On Mon, Mar 17, 2014 at 2:32 PM, WANG Cheng D <Cheng.d.Wang@alcatel-sbell.com.cn> wrote:

Dear all,

I am not clear about the ‘vcpu’ element for CPU allocation. I allocated 1 vCPU to my container, after I started the container, I ran 4 computation-intensive tasks on the container. And I found all the 4 physical core are 100% used (my host has 4 physical cores and no other application ran on the host except the container). That is, all available cores were used by the container. I want to know how to give a hard limitation for CPU usage of a container.

So I don’t understand what ‘vcpu’ setting can be used for.

I know that another CPU allocation element ‘shares’ can also be used, but this elements only give a relative quota. If new containers are started, the CPU quota for the already started containers will change.

Regards,

Cheng

_______________________________________________
libvirt-users mailing list
libvirt-users@redhat.com
https://www.redhat.com/mailman/listinfo/libvirt-users