Re: bridge with a bonded device - slow rate in the guest machine

[David Ahern <daahern@cisco.com>]

On 05/20/11 03:12, Алексей Кашин wrote:
> Hi.
> Server with two gigabit NIC's. I'm trying to setup a bridge with a
> bonded device (2 links,balance-rr).
> host# cat /etc/network/interfaces
> auto lo
> iface lo inet loopback
> 
> auto bond0
> iface bond0 inet manual
>         slaves eth0 eth1
>         bond_mode balance-rr
>         bond_miimon 100
>         bond_updelay 200
>         bond_downdelay 200
> 
> auto br0
> iface br0 inet static
>         address <ip>
>         netmask <netmask>
>         gateway <gateway>
>         bridge_ports bond0
>         bridge_stp off
>         bridge_fd 0
>         bridge_maxwait 0
> 
> host# cat /etc/modprobe.d/bonding.conf
> alias bond0 bonding
> 
> On this host I've created few kvm virtual machines. It's created with
> next options.
> 
> host# virt-install \
>         --name="name" \
>         --ram=512 \
>         --arch=x86_64 \
>         --vcpus=1 \
>         --cpuset=0 \
>         --os-type=linux \
>         --os-variant="debiansqueeze" \
>         --hvm \
>         --virt-type kvm \
>         --accelerate \
>         --cdrom=/iso/debian-6.0.1a-amd64-netinst.iso \
>         --disk path=/dev/vg00/name,bus=virtio,cache=none,format=raw,sparse=false
> \
>         --network bridge=br0,model=virtio \
>         --autostart
> 
> When I try to download a file I can see that the rate is very low:
> 
> guest# wget http://mirror.yandex.ru/archlinux/iso/2010.05/archlinux-2010.05-core-dual.iso
> --2011-05-20 12:47:16--
> http://mirror.yandex.ru/archlinux/iso/2010.05/archlinux-2010.05-core-dual.iso
> Resolving mirror.yandex.ru... 213.180.204.183, 2a02:6b8:0:201::1
> Connecting to mirror.yandex.ru|213.180.204.183|:80... connected.
> HTTP request sent, awaiting response... 200 OK
> Length: 691011584 (659M) [application/x-iso9660-image]
> Saving to: Б-°archlinux-2010.05-core-dual.isoБ-?
> 
>  0% [
>                               ] 79,686      7.97K/s  eta 20h 24m
> 
> But, if i try to get this file from host machine, I can see that the
> rate is normal:
> 
> host# wget http://mirror.yandex.ru/archlinux/iso/2010.05/archlinux-2010.05-core-dual.iso
> --2011-05-20 08:56:35--
> http://mirror.yandex.ru/archlinux/iso/2010.05/archlinux-2010.05-core-dual.iso
> Resolving mirror.yandex.ru... 213.180.204.183, 2a02:6b8:0:201::1
> Connecting to mirror.yandex.ru|213.180.204.183|:80... connected.
> HTTP request sent, awaiting response... 200 OK
> Length: 691011584 (659M) [application/x-iso9660-image]
> Saving to: Б-°archlinux-2010.05-core-dual.isoБ-?
> 
> 21% [=================================>
>                               ] 150,837,182 26.5M/s  eta 24s
> 
> 
> If I broke bonding in the host machine and try to setup bridging on
> device eth0 without bonding, the rate in both host and virtual machine
> is normal.

Have you tried active-backup mode instead of balanced-rr for the bonding
device? I have used that setup in the past and did not see any
performance issues with it.

David


> 
> Host machine:
> CPU: model name      : Intel(R) Xeon(R) CPU           E5504  @ 2.00GHz
> KVM:
> # dpkg -l | grep kvm
> ii  qemu-kvm                            0.12.5+dfsg-5+squeeze1
> Full virtualization on x86 hardware
> Kernel:
> # uname -a
> Linux unixmon 2.6.32-5-amd64 #1 SMP Mon Mar 7 21:35:22 UTC 2011 x86_64 GNU/Linux
> Guests:
> All guest - GNU/Debian 6.0.1a amd64 with 2.6.32-5-amd64 #1 SMP Mon Mar
> 7 21:35:22 UTC 2011 x86_64 GNU/Linux kernel
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