October 2018 - Users - libvirt List Archives

[libvirt-users] bridge / ubuntu / no arp reply
by François Chenais 15 Oct '26

15 Oct '26

Hello I'm trying to setup a bridged guest on an ubuntu 13.10 but it doesn't work. (Everything is ok with NAT) Network sniffing shows that arp replies don't come back to the guest. Test 1 ------ Guest : ping host_bridge_ip (ok) Test 2 ------ Guest: ping other_lan_host (KO) other_lan_host - receives arp who-is request - sends arp reply - arp -a shows the guest macaddr => Guest doesn't receive reply Test 3 ------ other_lan_host ping the Guest (KO) - arp -a shows "incomplete" addr - Guest receives nothing On Host ------- network tcpdump on bridge or vnet interfaces shows request but no reply ... Thanks in advance for help or ideas François

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[libvirt-users] [virtual interface] detach interface during boot succeed with no changes
by Yalan Zhang 08 Sep '22

08 Sep '22

Hi guys, when I detach an interface from vm during boot (vm boot not finished), it always fail. I'm not sure if there is an existing bug. I have confirmed with someone that for disk, there is similar behavior, if this is also acceptable? # virsh destroy rhel7.2; virsh start rhel7.2 ;sleep 2; virsh detach-interface rhel7.2 network 52:54:00:98:c4:a0; sleep 2; virsh dumpxml rhel7.2 |grep /interface -B9 Domain rhel7.2 destroyed Domain rhel7.2 started Interface detached successfully <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/> </controller> <interface type='network'> <mac address='52:54:00:98:c4:a0'/> <source network='default' bridge='virbr0'/> <target dev='vnet0'/> <model type='rtl8139'/> <alias name='net0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/> </interface> When I detach after the vm boot, expand the sleep time to 10, it will succeed. # virsh destroy rhel7.2; virsh start rhel7.2 ;sleep 10; virsh detach-interface rhel7.2 network 52:54:00:98:c4:a0; sleep 2; virsh dumpxml rhel7.2 |grep /interface -B9 Domain rhel7.2 destroyed Domain rhel7.2 started Interface detached successfully ------- Best Regards, Yalan Zhang IRC: yalzhang Internal phone: 8389413

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[libvirt-users] Add Virtlyst to the list of libvirt users
by Daniel Nicoletti 23 Sep '20

23 Sep '20

Hi, I've just released v1.0.0 of Virtlyst[1] a web tool to manage VMs using Qt/C++/Cutelyst https://dantti.wordpress.com/2018/04/19/announcing-virtlyst-a-web-interface… Thanks. 1 - https://github.com/cutelyst/Virtlyst -- Daniel Nicoletti KDE Developer - http://dantti.wordpress.com

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[libvirt-users] Question about disabling UFO on guest
by Bao Nguyen 05 Aug '20

05 Aug '20

Hello everyone, I would like to ask a question regarding to disable UFO of virtio vNIC in my guest. I have read the document at https://libvirt.org/formatdomain.html *host* The csum, gso, tso4, tso6, ecn and ufo attributes with possible values on and off can be used to turn off host offloading options. By default, the supported offloads are enabled by QEMU. *Since 1.2.9 (QEMU only)* The mrg_rxbuf attribute can be used to control mergeable rx buffers on the host side. Possible values are on (default) and off. *Since 1.2.13 (QEMU only)* *guest* The csum, tso4, tso6, ecn and ufo attributes with possible values on and off can be used to turn off guest offloading options. By default, the supported offloads are enabl ed by QEMU. *Since 1.2.9 (QEMU only)* Then I disabled UFO on my vNIC on guest as the following configuration <devices> <interface type='network'> <source network='default'/> <target dev='vnet1'/> <model type='virtio'/> <driver name='vhost' txmode='iothread' ioeventfd='on' event_idx='off' queues='5' rx_queue_size='256' tx_queue_size='256'> *<host gso='off' ufo='off' />* *<guest ufo='off'/>* </driver> </interface> </devices> Then I reboot my node to get the change effect and it works. However, can I disable the UFO without touching the host OS? or it always has to disable on both host and guest like that? Thanks, Brs, Natsu

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[libvirt-users] lvm vs qcow (on NVMe)
by lejeczek 26 Nov '18

26 Nov '18

hi guys, anybody observed, maybe has measured performance difference between the two with qemu quests(windows OS)? Any conclusions, recommendations? many thanks, L.

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[libvirt-users] Libvirt access control drivers
by Anastasiya Ruzhanskaya 21 Nov '18

21 Nov '18

Hello! According to the documentation access control drivers are not in really "good condition". There is a polkit, but it can distinguish users only according the pid. However, I have met some articles about more fine-grained control and about selinux drivers for libvirt? So, what is the status now? Should I implement something by myself if I want access based on login, are their instructions how to write these drivers or there is smth already?

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[libvirt-users] libvirt with persistent device names
by Jan Marquardt 07 Nov '18

07 Nov '18

Hi, I am trying to create a logical volume storage pool with persistent device names for the block devices, because I can't/don't want to ensure that /dev/sd* names are persistent through reboots. virsh # pool-define-as web2067 logical - - /dev/disk/by-path/pci-0000:18:00.0-scsi-0:2:2:0 web2067 /dev/web2067 virsh # pool-build web2067 These two steps work as expected and the pv and the vg get created, but when I try to start the pool I get the following error: virsh # pool-start web2067 error: Failed to start pool web2067 error: unsupported configuration: cannot find any matching source devices for logical volume group 'web2067' If I do the same steps just with /dev/sdX instead of /dev/disk/by-path/..., the pool gets created correctly. This looks like a bug for me or am I wrong? If this is the case, is this and known issue and fixed in later versions? I am running Ubuntu 18.04 with libvirt in version 4.0.0. Best Regards Jan

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[libvirt-users] Questions regarding migration from QEMU to libvirt
by Rodrigo Siqueira 06 Nov '18

06 Nov '18

Hi, My colleagues and I have a set of scripts that we use to automate our daily tasks related to the Linux Kernel. As a result, most of our code relies on the QEMU features; and recently we decided use libvirt instead of QEMU. However, we have some questions, and I would like to know if someone could help us. Follows: 1) Import our QEMU images with virsh Currently, we import the QEMU VMs with virt-install. Is it possible to automatically discover the distro variant of a QEMU image in order to use it in the “--os-variant” option? Here is how we register a VM: https://github.com/rodrigosiqueira/kworkflow/pull/23/files#diff-70617d452b0… 2) The requirement of sudo to create a network When we register our VM, we want to keep the ssh working well. However, every time we register a VM we create a new network bridge as a result it requires sudo. Is it possible to avoid this? Or at least make this a single action? Here is how we handled this: * The code for register: https://github.com/rodrigosiqueira/kworkflow/pull/23/files#diff-70617d452b0… * The configuration file that we adopted as a default: https://github.com/rodrigosiqueira/kworkflow/pull/23/files#diff-d8c16482496… 3) When using libvirt it changes the owner of our image If we try to use libvirt, it changes the ownership of our QEMU images (root). We fixed it by changing the file “/etc/libvirt/qemu.conf”, and switch the option dynamic_ownership to “0”. What is the impact of that change? Is it dangerous? There is a way to avoid this change? Finally, here is the full code of the libvirt part: https://github.com/rodrigosiqueira/kworkflow/pull/23/files Thanks Best Regards -- Rodrigo Siqueira http://siqueira.tech Graduate Student Department of Computer Science University of São Paulo

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[libvirt-users] Windows guest skipping chkdsk if using Spice display
by Gionatan Danti 05 Nov '18

05 Nov '18

Hi all, as per subject, when a Windows guest using a Spice display is rebooted with a planned chkdsk, the consistency check is always skipped. It seems that the Spice display issues some "phantom" keystrokes, which are then intended by Windows as the "skip chkdsk at boot" signal. I tried to use a Spice display with no additional features (ie: USB redirection), but to no avail. To workaround the problem I must use a VNC display, which is less featureful than the Spice one. My system and package versions are: CentOS 7.5 x86-64 spice-gtk3-0.34-3.el7_5.1.x86_64 spice-server-0.14.0-2.el7_5.4.x86_64 spice-glib-0.34-3.el7_5.1.x86_64 libvirt-3.9.0-14.el7_5.7.x86_64 qemu-kvm-ev-2.10.0-21.el7_5.4.1.x86_64 It seems I am not the only one experiencing this problem: http://seifesrants.blogspot.com/2016/07/ghost-keystrokes-with-libvirt-kvm-s… Any suggestion? Thanks. -- Danti Gionatan Supporto Tecnico Assyoma S.r.l. - www.assyoma.it email: g.danti(a)assyoma.it - info(a)assyoma.it GPG public key ID: FF5F32A8

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[libvirt-users] How to change the default connection of 'virsh' tool from 'qemu' to 'xen' ?
by Minjun Hong 02 Nov '18

02 Nov '18

Hi. Thanks to help of this mailing list (especially Jim Fehlig), I have finished setup of libvirt. However, there is something weird. It is that I installed libvirt on 5 servers but the default connection of one of them is 'qemu:///' even if those of the others are all 'xen:///'. I searched how to change it but, I only found a bypass adding " LIBVIRT_DEFAULT_URI='xen:///' " in my .bashrc file. Currently, value of the variable (LIBVIRT_DEFAULT_URI) is set to 'qemu:///'. Since the bypass makes the virtualization type of the server visible 'qemu' to the open stack, I have to change libvirt configuration. I also checked some configure files under '/etc/libvirt', such as libvirt.conf, libvirtd.conf and libxl.conf. But I have no idea, how and what to change. Please give me some advise. It will be a big help for me. Thanks.

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