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[libvirt-users] TCP reset (RST) networking issue (maybe was 'Sporadic network issues")
by Brian Fallik 10 Aug '10

10 Aug '10

Hi, I'm seeing a very similar problem to the thread "Sporadic networking issues" [1]. In our setup, some TCP operations receive unexpected RST packets when executed on the guest. I can see these RST packets via wireshark but can't explain their source. We originally 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 is configured as described in "Routed network config". One anomoly I notice is that our configuration is missing the 'mode' and 'dev' attributes of the 'forward' node. Not sure if that makes a difference, especially since networking seems to mostly work. I've tried this with both virtio and e1000 drivers with no difference. I tried Jeremy's suggestion to limit the host to start a single guest but that did not seem to have an impact. One thing I wonder is if I'm resetting the libvirt correctly to make this change. I did not reboot the host, but I did shutdown the guests, shutdown the default network, verified that no kvm was running and no tap/bridge devices existed, undefined the Hardy domain, then restarted the default network and started the Lucid kvm. Does that sound correct? Anyone have suggestions for further debugging or pointer(s) to existing related bugs? My search didn't turn up anything obvious. I'm very eager to resolve this issue since it's blocking our ability to use the VMs. Thanks, brian 1 - https://www.redhat.com/archives/libvirt-users/2010-August/msg00012.html

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[libvirt-users] renaming a domain?
by Igor Serebryany 10 Aug '10

10 Aug '10

Hi, I'm trying to figure out if libvirt supports a domain rename feature, like xen's "xm rename" command. I couldn't find anything in the docs suggesting such a function. Am I missing something? Thanks! --Igor

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[libvirt-users] Sporadic network issues
by jeremy avnet 09 Aug '10

09 Aug '10

I'm seeing this problem with both the virtio and e1000 driver with both linux and windows guests. About 5 - 10% of the VMs I launch have network problems. They seem to always get an IP from the DHCP server (dnsmasq), but afterwards either they can not make an outside network connection or they lose connectivity at a later time. Sometimes the connectivity comes back, sometimes it doesn't. It's very sporadic and there doesn't seem to be any rhyme or reason to it. The network is configured like "Routed network config" described here: http://libvirt.org/formatnetwork.html#examplesRoute The host machines are on Ubuntu 10.04. We were using the default Lucid packages (libvirt 0.7.5 / qemu 0.12.3), but I have upgraded us to libvirt 0.8.1 and qemu 0.12.4. I believe this has helped reduce the failure rate, but it still persists. Has anyone else had this problem or is there some suggestions for things to look into? Thank you. .:. jeremy

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[libvirt-users] 0.8.3 make error
by Haidong Zhu 09 Aug '10

09 Aug '10

OS: Ubuntu 9.04 Error output: CC libvirt_parthelper-parthelper.o CCLD libvirt_parthelper libvirt_parthelper-parthelper.o: In function `main': /home/yoyoadm/libvirt-0.8.3/src/storage/parthelper.c:105: undefined reference to `ped_device_get' /home/yoyoadm/libvirt-0.8.3/src/storage/parthelper.c:119: undefined reference to `ped_disk_new' /home/yoyoadm/libvirt-0.8.3/src/storage/parthelper.c:125: undefined reference to `ped_disk_next_partition' collect2: ld returned 1 exit status make[3]: *** [libvirt_parthelper] Error 1 make[3]: Leaving directory `/home/yoyoadm/libvirt-0.8.3/src' make[2]: *** [all] Error 2 make[2]: Leaving directory `/home/yoyoadm/libvirt-0.8.3/src' make[1]: *** [all-recursive] Error 1 make[1]: Leaving directory `/home/yoyoadm/libvirt-0.8.3' make: *** [all] Error 2

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[libvirt-users] howto setup linux guest with 2 nics
by Jan Paulini 06 Aug '10

06 Aug '10

hi, i have the following situation. my host system is running debian lenny and kvm. i have 2 ethernet interfaces of which i like to use eth0 for administration of the server itself without traffic from any guest systems. eth1 is connected to a different switch where i have numerous vlans. i have successfully setup a guest running virt-install using a bridge interface on the host system. here the debian config for br1 which i used: auto eth1.700 iface eth1.700 inet manual auto br1 iface br1 inet manual bridge_ports eth1.700 bridge_fd 9 bridge_hello 2 bridge_maxage 12 bridge_stp off i was now looking into the xml file for the guest hoping to find a way to use 2 ethernet interfaces for the guest one on br1 and another on br2 where br2 would be configures as br1 above on the host, just in a different vlan. how can i do that ? the network section of the xml fine lookes like this: <interface type='bridge'> <mac address='54:52:00:xx:xx:xx'/> <source bridge='br1'/> <model type='virtio'/> </interface> is there possibly a way of installing a guest with virt-install to give the guest eth0 and eth1 which are in different vlans on the hosts eth1 ? thanks for your help ! Jan

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[libvirt-users] How to force the use of virtio as the guest network driver
by Tony Lewis 06 Aug '10

06 Aug '10

I'm running KVM on a standard Debian Lenny host, and I seem to be hitting the problem identified here: http://serverfault.com/questions/123566/is-anyone-using-kvm-in-production My symptom is that using rsync over SSH to transfer files into the guest gets slower and slower, and then grinds to a halt, and the machine becomes unreachable. It seems that I should be using the virtio driver, but I can't seem to make it load. The KVM guest has the virtio module, (a la find /lib/modules -name \*virtio\*) but when I try to force it by setting <model type="virtio"/> in the XML configuration, it seems to make no difference. I see that as per http://libvirt.org/formatdomain.html , "qemu -net nic,model=? /dev/null" returns the following: "ne2k_isa i82551 i82557b i82559er ne2k_pci pcnet rtl8139", but I have no qemu-kvm binary. Not sure if that's a telling symptom or not. Host kernel is 2.6.26-2-openvz-amd64, KVM version is 72+dfsg-5~lenny5, libvirt version is 0.4.6-10, all of which look good enough to use virtio according to http://wiki.libvirt.org/page/Virtio . Thanks, Tony Lewis

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[libvirt-users] performance with libvirt and kvm
by Nirmal Guhan 04 Aug '10

04 Aug '10

Hi, I am seeing a performance degradation while using libvirt to start my vm (kvm). vm is fedora 12 and host is also fedora 12, both with 2.6.32.10-90.fc12.i686. Here are the statistics from iperf : >From VM: [ 3] 0.0-30.0 sec 199 MBytes 55.7 Mbits/sec >From host : [ 3] 0.0-30.0 sec 331 MBytes 92.6 Mbits/sec libvirt command as seen from ps output : /usr/bin/qemu-kvm -S -M pc-0.11 -enable-kvm -m 512 -smp 1 -name f12kvm1 -uuid 9300bfe2-2b9c-d9f0-3b03-9c7fe9934393 -monitor unix:/var/lib/libvirt/qemu/f12kvm1.monitor,server,nowait -boot c -drive file=/var/lib/libvirt/f12.img,if=ide,bus=0,unit=0,boot=on,format=raw -drive if=ide,media=cdrom,bus=1,unit=0,format=raw -net nic,macaddr=52:54:00:51:7c:39,vlan=0,model=virtio,name=net0 -net tap,fd=21,vlan=0,name=hostnet0 -serial pty -parallel none -usb -vnc 127.0.0.1:0 -k en-us -vga cirrus -balloon virtio If I start a similar vm using qemu-kvm directly, the performance matches with the host. qemu kvm : [ 3] 0.0-30.0 sec 329 MBytes 91.9 Mbits/sec TCP window size is 64K for all the cases. Command used : qemu-kvm vdisk.img -m 512 -net nic,model=virtio macaddr=$macaddress -net tap,script=/etc/qemu-ifup Any clues? Thanks, Nirmal

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[libvirt-users] libvirt and lxc
by Nirmal Guhan 03 Aug '10

03 Aug '10

Is anyone using libvirt for lxc ? I am trying to do so and running into an issue. The system container starts fine with lxc tools and am able to connect to it. Here is the snippet of my xml file (rest is same as in http://libvirt.org/drvlxc.html) <devices> <emulator>/usr/libexec/libvirt_lxc</emulator> <filesystem type='mount'> <source dir='/lxc/f12'/> <target dir='/'/> </filesystem> <interface type='bridge'> <mac address='52:54:00:82:87:64'/> <source bridge='br0'/> <target dev='tap0'/> </interface> <console type='pty'> <target port='0'/> </console> </devices> Am able to start the container but when I do console : virsh # console f12lxc Connected to domain f12lxc Escape character is ^] <<hangs here and I press enter, it destroys the domain>> virsh # Am running Fedora 12 with 2.6.32.10-90.fc12.i686. I changed target dev='tap0' to 'veth' and no change in the behavior. Please help. Thanks, Nirmal

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[libvirt-users] virDomainSetSchedulerParameters() does not support KVM?
by Zhang Qian 29 Jul '10

29 Jul '10

Hi, I have one RHEL 5.5 Xen box and one RHEL 5.5 KVM box. In the Xen box, the following command works well: $ virsh schedinfo RHELu3T Scheduler : credit weight : 256 cap : 0 But in KVM box, it can not work: $ virsh schedinfo RHEL5u3 Scheduler : Unknown error: this function is not supported by the hypervisor: virDomainGetSchedulerType Is it because that the libvirt APIs virDomainGetSchedulerParameters() and virDomainSetSchedulerParameters() does not support KVM? Is there any plan for libvirt to support that? Or any equivalent in libvirt can be used to do the same thing for KVM？ Thanks! Qian

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[libvirt-users] Too many active clients?
by jeremy avnet 29 Jul '10

29 Jul '10

Hello, I'm receiving a lot of these since a couple of days ago: libvirtd: 16:30:10.960: error : qemudDispatchServer:1282 : Too many active clients (20), dropping connection I'm trying to figure out where all these active clients are coming from. I have a daemon running the interacts with libvirtd, but it only creates two long-lived connections (I'm very sure). What constitutes an active connection? The only other libvirtd access that goes on are some quick lived munin process which connect in various ways and using virsh on the command line. Libvirt version 0.7.5-5ubuntu27 on Ubuntu 10.04. Thanks! .:. jeremy

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