[one-users] Some questions about overcommitment in OpenNebula 4.2 using KVM

[Gerry O'Brien]

On 16/10/2013 20:40, Michał Madziar wrote:
> On 2013-10-16 21:00, Gerry O'Brien wrote:
>> On 16/10/2013 17:19, Michał Madziar wrote:
>>> On 2013-10-16 14:42, Gerry O'Brien wrote:
>>>> Hi,
>>>>
>>>>       Do you know if the CPU parameter has any effect on the amount of
>>>> real cpu used, e.g. if I set the CPU parameter to 0.1 will this limit
>>>> the actual cpu usage?
>>> libvirt uses cgroups, so yes, it does.
>> cgroups do not seem to be enabled with kvm. Am I correct in assuming
>> this?
> Check if /sys/fs/cgroup/cpu/libvirt/qemu/ exists and it's contents, if
> cgroups are used cpu quotas can be checked with:
> find /sys/fs/cgroup/cpu/libvirt/qemu/ -name cpu.shares -exec echo '{}'
> \; -exec cat '{}' \;
>
>>>>       Also, can the monitor driver be  configured to report multiples of
>>>> memory and allow memory overcommitment in the same way?
>>> Just assign whatever you want to $total_memory in kvm.rb, but keep in
>>> mind that if ballooned/deduplicated pages will start to differ either
>>> swap will be used (which will probably kill the host) or oomkiller will
>>> kick in.
>>>
>>> Example:
>>> $total_cpu = 2000
>>> $free_cpu = $total_cpu - $used_cpu
>>> $total_memory = $total_memory.to_i+$free_memory.to_i
>>> $free_memory = $total_memory - $used_memory.to_i
>>> print_info("HYPERVISOR","kvm")
>>> #...
>>>
>>> Dashboard charts will look strange but it seems to work.
>>
>> Hi,
>>
>> This didn't work for me. I'm running 4.2. The scheduler has a capacity
>> test (see below). Any idea where the code for "get_requirements" lives?
> I didn't touch the scheduler, just patched the reporting script.
> On my system it exists in ~oneadmin/remotes/im/kvm.d/kvm.rb and is
> copied by ON (idr when exactly - restart?)  to /var/tmp/one/im/kvm.d/ on
> every host in cluster.
> I just added above lines near the end of script - before printing,
> copied it manually and about minute later changes were visible in chart.

Hi,
     This file get copied over to the host when oned is restarted. If 
you run it on the host it reports the increased memory size. However, 
the scheduler seems to ignore this. I'm running version 4.2. Is that 
what you are running?
>      
> _______________________________________________
> Users mailing list
> Users at lists.opennebula.org
> http://lists.opennebula.org/listinfo.cgi/users-opennebula.org


-- 
Gerry O'Brien

Systems Manager
School of Computer Science and Statistics
Trinity College Dublin
Dublin 2
IRELAND

00 353 1 896 1341