[ovirt-users] Network performance drop when compared to other hypervisor with vhost_net on for UDP

[Martin Pavlík]

Check files under /etc/tune-profiles/

HTH

Martin Pavlik

RHEV QE

> On 14 Jan 2015, at 13:55, mad Engineer <themadengin33r at gmail.com> wrote:
> 
> Thanks Martin,
>                      How can we see the changes made by tuned?
> for "virtual guest" i see it changes scheduler to deadline.Is there
> any way to see what parameters each  profile is going to change
> 
> Thanks
> 
> On Wed, Jan 14, 2015 at 6:14 PM, Martin Pavlík <mpavlik at redhat.com> wrote:
>> Hi,
>> 
>> from the top of my head you could try to play with tuned both with guest and host
>> 
>> ###Install###
>> yum install tuned
>> /etc/init.d/tuned start
>> chkconfig tuned on
>> 
>> ###usage###
>> list the profile:
>> tuned-adm list
>> 
>> change your profile:
>> tuned-adm profile throughput-performance
>> 
>> maybe try to experiment with other profiles.
>> 
>> HTH
>> 
>> Martin Pavlik
>> RHEV QE
>> 
>>> On 14 Jan 2015, at 12:06, mad Engineer <themadengin33r at gmail.com> wrote:
>>> 
>>> I am running RHEL6.5 as Host and Guest on HP server.
>>> Server has 128G and 48 Core[with HT enabled.]
>>> 
>>> 3 VMs are running 2 pinned to first 24 PCPU with proper NUMA pinning,
>>> 
>>> Guests:
>>> 
>>> VM1:
>>> 6 VCPU  pinned to 6 PCPU NUMA node 1,with 16G RAM
>>> 
>>> VM2:
>>> 6 VCPU pinned to 6 PCPU on NUMA node 0,with 16G RAM
>>> 
>>> VM3:
>>> 2 VCPU ,no pinning,4G RAM
>>> 
>>> HOST
>>> host has 10 free CPU+24 HT threads which is not allocated and is available.
>>> Host also runs a small application that is single threaded,that uses ~4G RAM.
>>> 
>>> Total resource to host is 10 CPU+24 HT=34 and 92G unallocated RAM[VMS
>>> dont even use 70% of allocated RAM] also ksm is not running.
>>> 
>>> Networking:
>>> Uses linux bridge connected to 1Gbps eth0,with ip assigned on eth0
>>> [This IP is called for accessing application running on host]
>>> All vms use virtio and VHOST is on .
>>> 
>>> Traffic on virtual machines are ~3MBps and combined traffic on host is ~14MBps
>>> 
>>> "VHOST-pid-of-qemu-process" sometimes uses ~35% CPU.
>>> 
>>> 
>>> There is no packet loss,drop or latency,but the issue is with the same
>>> setup on Vmware with same sizing of virtual machines,with the only
>>> difference as application running on host has moved to fourth VM.So in
>>> Vmware there are 4 VMs.
>>> Application gives better number ie on KVM that number is 310 and on
>>> vmware it is 570.Application uses UDP to communicate.
>>> 
>>> I tried removing VHOST,still value is same.(I hope VHOST-NET UDP issue
>>> is solved)
>>> 
>>> Thanks for any help
>>> _______________________________________________
>>> Users mailing list
>>> Users at ovirt.org
>>> http://lists.ovirt.org/mailman/listinfo/users
>>