[Bug 616064] Re: Broken networking in kvm guests

[Serge Hallyn]

Thanks for the info, Anthony.  The wireshark info failed to download for
me.  Could you attach it here?

My only guess ATM is that it is a bad interaction with the physical
switch or router to which eth3 is attached.  I'd ask you to try with
different hardware, but I see you're running production VMs on there.

Can you tell us exactly (names and models) what hardware is physically
involved in the network leading up to eth3?

Perhaps we can insert a logging layer 2 firewall between the switch and
eth3 to see what is going on there.  Do you have a spare machine with
two NICs which could be used for that?

** Changed in: qemu-kvm (Ubuntu)
       Status: Incomplete => Confirmed

** Also affects: bridge-utils (Ubuntu)
   Importance: Undecided
       Status: New

** Also affects: linux (Ubuntu)
   Importance: Undecided
       Status: New

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https://bugs.launchpad.net/bugs/616064

Title:
  Broken networking in kvm guests

Status in “bridge-utils” package in Ubuntu:
  New
Status in “linux” package in Ubuntu:
  New
Status in “qemu-kvm” package in Ubuntu:
  Confirmed

Bug description:
  Binary package hint: qemu-kvm

  
  Some TCP operations receive unexpected reset (RST) packets when executed on the guest.  I can see these RST packets via
  Wireshark but can't explain their source.  This breaks certain (most) networking on the guest.

  I uncovered this when some 'git clone' operations failed with "Broken
  Pipe" in the guests.  I've been able to reproduce the same failures
  using scp and 'svn checkout'.  The failure occurs 80-90% of the time
  and 'svn checkout' seems to be the quickest to fail.  The same
  operations on the host are always successful.

  My setup is a Lucid amd64 host with two guests (Lucid and Hardy, both
  i386, using kvm).  Networking seems to mostly work.  I can maintain
  persistent ssh connections to the guest and some networking operations
  from the guest (ie. ping) never fail.  However, the git-clone/scp/svn-
  checkout operations fail almost all the time.  I've tried this with
  both virtio and e1000 drivers with no difference.

  This may be similar to some of the behavior reported in bug 584048 but
  not the final patch referenced in comment 27.  I built a custon deb
  including the upstream patch for testing and it had no effect.

  $ lsb_release -rd
  Description:	Ubuntu 10.04.1 LTS
  Release:	10.04

  $ apt-cache policy qemu-kvm
  qemu-kvm:
    Installed: 0.12.3+noroms-0ubuntu9.2
    Candidate: 0.12.3+noroms-0ubuntu9.2
    Version table:
   *** 0.12.3+noroms-0ubuntu9.2 0
          500 http://us.archive.ubuntu.com/ubuntu/ lucid-updates/main Packages
          100 /var/lib/dpkg/status
       0.12.3+noroms-0ubuntu9 0
          500 http://us.archive.ubuntu.com/ubuntu/ lucid/main Packages

  ProblemType: Bug
  DistroRelease: Ubuntu 10.04
  Package: kvm 1:84+dfsg-0ubuntu16+0.12.3+noroms+0ubuntu9.2
  ProcVersionSignature: Ubuntu 2.6.32-24.39-server 2.6.32.15+drm33.5
  Uname: Linux 2.6.32-24-server x86_64
  Architecture: amd64
  Date: Tue Aug 10 16:39:24 2010
  InstallationMedia: Ubuntu-Server 10.04 "Lucid Lynx" - Beta amd64 (20100406.1)
  KvmCmdLine:
   UID        PID  PPID  C    SZ   RSS PSR STIME TTY          TIME CMD
   root     17641     1  1 2174883 1087144 1 15:42 ?      00:00:59 /usr/bin/kvm -S -M pc-0.12 -cpu qemu32 -enable-kvm -m 8192 -smp 8 -name hound-lucid -uuid 0e32438c-cb4d-1eb9-a560-f25c89c1dbf6 -chardev socket,id=monitor,path=/var/lib/libvirt/qemu/hound-lucid.monitor,server,nowait -monitor chardev:monitor -boot c -drive file=/opt/hound-lucid,if=virtio,index=0,boot=on -drive if=ide,media=cdrom,index=2 -net nic,macaddr=52:54:00:61:7e:c0,vlan=0,model=virtio,name=virtio.0 -net tap,fd=59,vlan=0,name=tap.0 -chardev pty,id=serial0 -serial chardev:serial0 -parallel none -usb -vnc 127.0.0.1:0 -k en-us -vga cirrus
  MachineType: IBM IBM System x3400 M2 Server -[7836AC1]-
  ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.32-24-server root=UUID=7d9adc6b-cfec-42fa-b469-bc09ccd24478 ro quiet
  ProcEnviron:
   PATH=(custom, user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  SourcePackage: qemu-kvm
  dmi.bios.date: 11/20/2009
  dmi.bios.vendor: IBM Corp.
  dmi.bios.version: -[Y4E131BUS-1.02]-
  dmi.board.name: 49Y6715
  dmi.board.vendor: IBM
  dmi.board.version: GA
  dmi.chassis.type: 23
  dmi.chassis.vendor: IBM
  dmi.chassis.version: GA
  dmi.modalias: dmi:bvnIBMCorp.:bvr-[Y4E131BUS-1.02]-:bd11/20/2009:svnIBM:pnIBMSystemx3400M2Server-[7836AC1]-:pvr06:rvnIBM:rn49Y6715:rvrGA:cvnIBM:ct23:cvrGA:
  dmi.product.name: IBM System x3400 M2 Server -[7836AC1]-
  dmi.product.version: 06
  dmi.sys.vendor: IBM

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