After moving to 3.5 kernel I haven't seen it, even at 3x traffic which used
to cause it
On Mar 25, 2014 9:06 PM, "Dewey McDonnell" wrote:
> My web search reveals this problem has been around for years and most
> posts conclude that the problem continues. After solving my tap0 TX
> packets dropped problem, I find that my VM network has random freezes a
> few times each day. Many bloggers on this subject say this VM network
> freeze is difficult to reproduce. Not for me! I can cause a network
> freeze on my VM in a heartbeat. Like many others, all I need to do is
> start a data transfer over the bridge (FTP 2Kb file or larger). When the
> freeze happens, ifconfig tap0 says overruns:1. This is QEMU version
> 1.6.2 without KVM on CentOS 6.5 version 2.6.32-431.
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/997978
>
> Title:
> KVM images lose connectivity with bridged network
>
> Status in OpenStack Compute (Nova):
> Invalid
> Status in "qemu-kvm" package in Ubuntu:
> Fix Released
> Status in "qemu-kvm" source package in Precise:
> Fix Released
>
> Bug description:
> =
> SRU Justification:
> 1. Impact: networking breaks after awhile in kvm guests using virtio
> networking
> 2. Development fix: The bug was fixed upstream and the fix picked up in
> a new
> merge.
> 3. Stable fix: 3 virtio patches are cherrypicked from upstream:
> a821ce5 virtio: order index/descriptor reads
> 92045d8 virtio: add missing mb() on enable notification
> a281ebc virtio: add missing mb() on notification
> 4. Test case: Create a bridge enslaving the real NIC, and use that as
> the bridge
> for a kvm instance with virtio networking. See comment #44 for
> specific test
> case.
> 5. Regression potential: Should be low as several people have tested the
> fixed
> package under heavy load.
> =
>
> System:
> ---
> Dell R410 Dual processor 2.4Ghz w/16G RAM
> Distributor ID: Ubuntu
> Description:Ubuntu 12.04 LTS
> Release:12.04
> Codename: precise
>
> Setup:
> -
> We're running 3 KVM guests, all Ubuntu 12.04 LTS using bridged
> networking.
>
> From the host:
> # cat /etc/network/interfaces
> auto br0
> iface br0 inet static
> address 212.XX.239.98
> netmask 255.255.255.240
> gateway 212.XX.239.97
> bridge_ports eth0
> bridge_fd 9
> bridge_hello 2
> bridge_maxage 12
> bridge_stp off
>
> # ifconfig eth0
> eth0 Link encap:Ethernet HWaddr d4:ae:52:84:2d:5a
> UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
> RX packets:11278363 errors:0 dropped:3128 overruns:0 frame:0
> TX packets:14437384 errors:0 dropped:0 overruns:0 carrier:0
> collisions:0 txqueuelen:1000
> RX bytes:4115980743 (4.1 GB) TX bytes:5451961979 (5.4 GB)
> Interrupt:36 Memory:da00-da012800
>
> # ifconfig br0
> br0 Link encap:Ethernet HWaddr d4:ae:52:84:2d:5a
> inet addr:212.XX.239.98 Bcast:212.XX.239.111
> Mask:255.255.255.240
> inet6 addr: fe80::d6ae:52ff:fe84:2d5a/64 Scope:Link
> UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
> RX packets:1720861 errors:0 dropped:0 overruns:0 frame:0
> TX packets:1708622 errors:0 dropped:0 overruns:0 carrier:0
> collisions:0 txqueuelen:0
> RX bytes:210152198 (210.1 MB) TX bytes:300858508 (300.8 MB)
>
> # brctl show
> bridge name bridge id STP enabled interfaces
> br0 8000.d4ae52842d5a no eth0
>
> I have no default network configured to autostart in libvirt as we're
> using bridged networking:
> # virsh net-list --all
> Name State Autostart
> -
> default inactive no
>
> # arp
> Address HWtype HWaddress Flags Mask
>Iface
> mailer03..com ether 52:54:00:82:5f:0f C
> br0
> mailer01..com ether 52:54:00:d2:f7:31 C
> br0
> mailer02..com ether 52:54:00:d3:8f:91 C
> br0
> dxi-gw2..comether 00:1a:30:2a:b1:c0 C
> br0
>
> From one of the guests:
>
> mailer01
> d41d1355-84e8-ae23-e84e-227bc0231b97
> 2097152
> 2097152
> 1
>
> hvm
>
>
>
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>
>
> destroy
> restart
> destroy
>
> /usr/bin/kvm
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> function='0x1'/>
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> function='0x0'/>
