[one-users] KVM process at 99% CPU

[Javier Fontan]

Most, if not all, modern operating systems set the CPU to sleep mode
when they don't need to be used. The problem here is that the VMs are
not running a OS but a boot loader and it does not implement this
feature so it is using all the CPU cycles doing nothing. In this
regard KVM nor OpenNebula can help.

The only tip I can give you is to use cgroups to limit the total
amount of CPU a VM can use:

http://opennebula.org/documentation:rel4.2:kvmg#working_with_cgroups_optional

On Thu, Nov 7, 2013 at 4:38 PM, Daniel Dehennin
<daniel.dehennin at baby-gnu.org> wrote:
> Hello,
>
> On our 3.8 dual-node ONE I got this morning a OVERLOADED node with load
> average of 35.
>
> I found one my own VMs eating 99% CPU, it was just booted and waiting
> at ISO boot menu prompt.
>
> It looks to be related to KVM as I reproduce it on a 4.2.
>
> I can reproduce it by defining a template using an Ubuntu Server AMD64 ISO
> and instanciate it.
>
> I just let the VMs at ISO boot menu, and the KVM process quickly eat 99%
> of CPU.
>
> If someone has an idea.
>
> Here is the template:
>
>     oneadmin at nebula:~$ onetemplate show 17
>     TEMPLATE 17 INFORMATION
>     ID             : 17
>     NAME           : Install ISO AMD64 20G
>     USER           : eole
>     GROUP          : oneadmin
>     REGISTER TIME  : 10/11 19:29:17
>
>     PERMISSIONS
>     OWNER          : um-
>     GROUP          : ---
>     OTHER          : ---
>
>     TEMPLATE CONTENTS
>     CONTEXT=[
>       NETWORK="YES",
>       SSH_PUBLIC_KEY="$USER[SSH_PUBLIC_KEY]" ]
>     CPU="0.2"
>     DISK=[
>       IMAGE_ID="0" ]
>     DISK=[
>       CACHE="none",
>       IMAGE_ID="43" ]
>     FEATURES=[
>       ACPI="yes",
>       PAE="no" ]
>     GRAPHICS=[
>       KEYMAP="fr",
>       LISTEN="0.0.0.0",
>       TYPE="VNC" ]
>     INPUT=[
>       BUS="usb",
>       TYPE="tablet" ]
>     MEMORY="768"
>     NIC=[
>       MODEL="virtio",
>       NETWORK_ID="1" ]
>     OS=[
>       ARCH="x86_64",
>       BOOT="hd" ]
>     VCPU="2"
>
> And here the ISO:
>
>     oneadmin at nebula:~$ oneimage show 43
>     IMAGE 43 INFORMATION
>     ID             : 43
>     NAME           : Ubuntu 13.10 server AMD64
>     USER           : eole
>     GROUP          : oneadmin
>     DATASTORE      : ISO
>     TYPE           : CDROM
>     REGISTER TIME  : 11/07 16:29:06
>     PERSISTENT     : No
>     SOURCE         :
>     /var/lib/one//datastores/100/39670c51a99879ca3e221d5fc8027dce
>     PATH           : /var/tmp/thin-body20131107-1782-yqfomp
>     SIZE           : 672M
>     STATE          : used
>     RUNNING_VMS    : 1
>
>     PERMISSIONS
>     OWNER          : um-
>     GROUP          : ---
>     OTHER          : ---
>
>     IMAGE TEMPLATE
>     DEV_PREFIX="hd"
>     DRIVER="raw"
>
>     VIRTUAL MACHINES
>
>         ID USER     GROUP    NAME            STAT UCPU    UMEM HOST    TIME
>        117 eole     oneadmin userver-test    runn   99    768M nebula  0d 00h06
>
> Regards.
>
> --
> Daniel Dehennin
> Récupérer ma clef GPG:
> gpg --keyserver pgp.mit.edu --recv-keys 0x7A6FE2DF
>
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>



-- 
Javier Fontán Muiños
Developer
OpenNebula - The Open Source Toolkit for Data Center Virtualization
www.OpenNebula.org | @OpenNebula | github.com/jfontan