[one-users] Relationship of cpu usages

[Christoph Pleger]

Hello,

> We have the "logical" OpenNebula level enforcement, and the hypervisor
> level.
>
> First one: the OpenNebula scheduler will not allocate more cpu/memory than
> the Host reports as available.
>
> Hypervisor level reservation: cgroups for kvm, credit scheduler for xen,
> and the esx cpu scheduler for vmware

So, if I understand correctly, it is like following:

1. One real CPU core represents 100 percent of CPU capacity.

2. The CPU value in VM Templates is related to one CPU core.

3. From the CPU values, OpenNebula calculates how much of the capacity of
a cloud node is already used.

4. If a node does not have enough CPU capacity for a new VM, the VM is not
started on that node.

5. For the kvm hypervisor, OpenNebula can use the cgroup feature to
enforce relationship between CPU values of different VMs.

Is this correct?

>>  I am also wondering why, in sunstone, one cloud node with one VM
>> running
>> on it shows a CPU usage of 6400. I thought that this is because the user
>> set CPU=8, VCPU=8 and 8*8=64, but if CPU= is related to one physical
>> CPU,
>> that cannot be true ...
>>
>
> Can you please paste the output of 'onehost show <id>' ?

HOST 151 INFORMATION
ID                    : 151
NAME                  : node18
CLUSTER               : -
STATE                 : MONITORED
IM_MAD                : im_kvm
VM_MAD                : vmm_kvm
VN_MAD                : ebtables
LAST MONITORING TIME  : 04/29 17:06:11

HOST SHARES
TOTAL MEM             : 252.4G
USED MEM (REAL)       : 9.1G
USED MEM (ALLOCATED)  : 8G
TOTAL CPU             : 6400
USED CPU (REAL)       : 384
USED CPU (ALLOCATED)  : 6400
RUNNING VMS           : 1

MONITORING INFORMATION
ARCH="x86_64"
CPUSPEED="2100"
FREECPU="6016.0"
FREEMEMORY="255101900"
HOSTNAME="cloudhost18"
HYPERVISOR="kvm"
MODELNAME="AMD Opteron(TM) Processor 6272 "
NETRX="0"
NETTX="0"
TOTALCPU="6400"
TOTALMEMORY="264614860"
USEDCPU="384.0"
USEDMEMORY="9512960"

Regards
  Christoph