I don't believe just rebooting a guest will cause a new KVM instance to load. As a test, I just rebooted a guest VM on a system here and the pid of the kvm process did not change. I think it may be possible that you are still running on the old software.
Also, to update my data point... On my server which was experiencing issues, I rebooted the host just to make sure everything was fresh. It's been about a month and I have not experienced the failure again. I was typically going a few weeks between issues. gary ----- Original Message ----- From: "Matt Hilt" <mjh...@gmail.com> To: g...@isgsoftware.net Sent: Tuesday, September 25, 2012 12:07:44 PM Subject: [Bug 997978] Re: KVM images lose connectivity with bridged network Soren, We have a 12.04 based OpenStack cluster with 4 host nodes running about 30 VMs currently. We performed the steps to add the kvm-network-hang repo and updated to the latest version on the host machines, then rebooted the instances. My understanding is that this should catch the update, since a new KVM command is run on reboot. I caught the first failure ~12 hours after the upgrade. It had the usual symptoms: networking loss, but the VM is still up and an active VNC session was possible. I thought I just might have missed a reboot on one of the VMs, so I didn't report anything. The second failure happened yesterday, but someone else caught it and rebooted the VM. As best we can tell after the fact, it looks like the usual failure (no full harddrive, or kernel panic, or anything that got logged). As I mentioned before, we used to see at least one failure per day, usually much more. This patch has at least reduced the occurence to a minimal amount. These non-deterministic bugs are hard to track down. -- 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: In Progress 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:da000000-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.xxxx.com ether 52:54:00:82:5f:0f C br0 mailer01.xxxx.com ether 52:54:00:d2:f7:31 C br0 mailer02.xxxx.com ether 52:54:00:d3:8f:91 C br0 dxi-gw2.xxxx.com ether 00:1a:30:2a:b1:c0 C br0 From one of the guests: <domain type='kvm' id='4'> <name>mailer01</name> <uuid>d41d1355-84e8-ae23-e84e-227bc0231b97</uuid> <memory>2097152</memory> <currentMemory>2097152</currentMemory> <vcpu>1</vcpu> <os> <type arch='x86_64' machine='pc-1.0'>hvm</type> <boot dev='hd'/> </os> <features> <acpi/> </features> <clock offset='utc'/> <on_poweroff>destroy</on_poweroff> <on_reboot>restart</on_reboot> <on_crash>destroy</on_crash> <devices> <emulator>/usr/bin/kvm</emulator> <disk type='file' device='disk'> <driver name='qemu' type='raw'/> <source file='/dev/mapper/vg_main-mailer01--root'/> <target dev='hda' bus='ide'/> <alias name='ide0-0-0'/> <address type='drive' controller='0' bus='0' unit='0'/> </disk> <disk type='file' device='disk'> <driver name='qemu' type='raw'/> <source file='/dev/mapper/vg_main-mailer01--swap'/> <target dev='hdb' bus='ide'/> <alias name='ide0-0-1'/> <address type='drive' controller='0' bus='0' unit='1'/> </disk> <controller type='ide' index='0'> <alias name='ide0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/> </controller> <interface type='bridge'> <mac address='52:54:00:d2:f7:31'/> <source bridge='br0'/> <target dev='vnet0'/> <model type='virtio'/> <alias name='net0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/> </interface> <serial type='pty'> <source path='/dev/pts/0'/> <target port='0'/> <alias name='serial0'/> </serial> <console type='pty' tty='/dev/pts/0'> <source path='/dev/pts/0'/> <target type='serial' port='0'/> <alias name='serial0'/> </console> <input type='mouse' bus='ps2'/> <graphics type='vnc' port='5900' autoport='yes' listen='127.0.0.1'> <listen type='address' address='127.0.0.1'/> </graphics> <video> <model type='cirrus' vram='9216' heads='1'/> <alias name='video0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/> </video> <memballoon model='virtio'> <alias name='balloon0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/> </memballoon> </devices> <seclabel type='dynamic' model='apparmor' relabel='yes'> <label>libvirt-d41d1355-84e8-ae23-e84e-227bc0231b97</label> <imagelabel>libvirt-d41d1355-84e8-ae23-e84e-227bc0231b97</imagelabel> </seclabel> </domain> From within the guest: # cat /etc/network/interfaces # The primary network interface auto eth0 iface eth0 inet static address 212.XX.239.100 netmask 255.255.255.240 network 212.XX.239.96 broadcast 212.XX.239.111 gateway 212.XX.239.97 # ifconfig eth0 Link encap:Ethernet HWaddr 52:54:00:d2:f7:31 inet addr:212.XX.239.100 Bcast:212.XX.239.111 Mask:255.255.255.240 inet6 addr: fe80::5054:ff:fed2:f731/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:5631830 errors:0 dropped:0 overruns:0 frame:0 TX packets:6683416 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:2027322829 (2.0 GB) TX bytes:2076698690 (2.0 GB) A commandline which starts the KVM guest: /usr/bin/kvm -S -M pc-1.0 -enable-kvm -m 2048 -smp 1,sockets=1,cores=1,threads=1 -name mailer01 -uuid d41d1355-84e8-ae23-e84e-227bc0231b97 -nodefconfig -nodefaults -chardev socket,id=charmonitor,path=/var/lib/libvirt/qemu/mailer01.monitor,server,nowait -mon chardev=charmonitor,id=monitor,mode=control -rtc base=utc -no-shutdown -drive file=/dev/mapper/vg_main-mailer01--root,if=none,id=drive-ide0-0-0,format=raw -device ide-drive,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0,bootindex=1 -drive file=/dev/mapper/vg_main-mailer01--swap,if=none,id=drive-ide0-0-1,format=raw -device ide-drive,bus=ide.0,unit=1,drive=drive-ide0-0-1,id=ide0-0-1 -netdev tap,fd=18,id=hostnet0 -device virtio-net-pci,netdev=hostnet0,id=net0,mac=52:54:00:d2:f7:31,bus=pci.0,addr=0x3 -chardev pty,id=charserial0 -device isa-serial,chardev=charserial0,id=serial0 -usb -vnc 127.0.0.1:0 -vga cirrus -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x4 Problem: ------------ Periodically (at least once a day), one or more of the guests lose network connectivity. Ping responds with 'host unreachable', even from the dom host. Logging in via the serial console shows no problems: eth0 is up, can ping the local host, but no outside connectivity. Restart the network (/etc/init.d/networking restart) does nothing. Reboot the machine and it comes alive again. I've verified there's no arp games going on on the primary host (the arp tables remain the same before - when it had connectivity - and after - when it doesn't. This is a critical issue affecting production services on the latest LTS release of Ubuntu. It's similar to an issue which was 'resolved' in 10.04 but appears to have risen its ugly head again. To manage notifications about this bug go to: https://bugs.launchpad.net/nova/+bug/997978/+subscriptions -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to qemu-kvm in Ubuntu. https://bugs.launchpad.net/bugs/997978 Title: KVM images lose connectivity with bridged network To manage notifications about this bug go to: https://bugs.launchpad.net/nova/+bug/997978/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
