CPU difference with proxmox 4.3 and vm?

[eislon]

I upgraded my cluster from proxmox 4.2 to 4.3 and I see on one vm a difference in the usage of the cpu!
In the GUI of proxmox it shows me 7,xx% usages of the cpu while in the vm I just have 0.7% cpu usage.
that is a big difference. I dont see it with my other vm's!

it is an LXC container, but I got another one running and its cpu usage is correct!

Is this a bug, or can anyone explain this behaviour?

See the screenshot I provided!

thanks.

 

[spirit]

They are always overhead, mainly for interrupts (network interrupts for example), which can use cpu on host without seeing them in guest.
Any special application running in this guest ?

 

[eislon]

No no special application running, but will build a test vm as this one is and look if it will behave the same way!
However I still think it is strange that I dont see it in the vm, this means that the proxmox host is doing stuff for the vm so it should show on the host processes then!

 

[spirit]

No no special application running, but will build a test vm as this one is and look if it will behave the same way!
However I still think it is strange that I dont see it in the vm, this means that the proxmox host is doing stuff for the vm so it should show on the host processes then!

It's normal that your guest vm is not seeing it, as the cpu is coming from qemu itself. (think of a virtual motherboard, your guest can't see chipset usage for example).
If you don't have nothing running inside your vm, can you try to remove virtual network interface. (could be big broadcast or multicast comming to vm interface)

 

[eislon]

It's normal that your guest vm is not seeing it, as the cpu is coming from qemu itself. (think of a virtual motherboard, your guest can't see chipset usage for example).
If you don't have nothing running inside your vm, can you try to remove virtual network interface. (could be big broadcast or multicast comming to vm interface)

Ok, well I just have to try and install all the same software to a identical vm and see with each software package added when this happens.

Thanks for your help.