April 2019 - 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] GVT-g - suboptimal user experience
by Alex Ivanov 20 May '19

20 May '19

Hi. In the current state of gvt-g the user experience is suboptimal. So my question is what are the ETAs for following features: 1. Accelerated virt-manager console using gvt-g device 2. Custom resolutions or dynamic resolution 3. UEFI VMs support (Windows guest) Thanks.

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[libvirt-users] Autodetecting backing file properties when using vol-create-as
by Gionatan Danti 06 May '19

06 May '19

Hi all, experimenting with vol-create-as, I think it should autodetect some data - filesize and backing file format, specifically. However, the current implementation require us to specify both filesize and backing file format. Considering that qemu-img already autodetects these data, there are any reason for the lack of autodetect by libvirt? Should I open a bugzilla issue? Below you can find a practical example of what I mean. System is CentOS Linux release 7.6.1810 (Core) with libvirt-4.5.0-10.el7_6.4.x86_64 Please let me know if I am missing something. Thanks. # create base file [root@singularity images]# qemu-img create base.qcow2 8G -f qcow2 Formatting 'base.qcow2', fmt=qcow2 size=8589934592 cluster_size=65536 lazy_refcounts=off refcount_bits=16 [root@singularity images]# qemu-img info base.qcow2 image: base.qcow2 file format: qcow2 virtual size: 8.0G (8589934592 bytes) disk size: 17K cluster_size: 65536 Format specific information: compat: 1.1 lazy refcounts: false refcount bits: 16 corrupt: false # create overlay1.qcow2 via qemu-img; note how backing file format is autodetected ("-f qcow2" regards the overlay file itself) [root@singularity images]# qemu-img create -b /var/lib/libvirt/images/base.qcow2 overlay1.qcow2 -f qcow2 Formatting 'overlay1.qcow2', fmt=qcow2 size=8589934592 backing_file=/var/lib/libvirt/images/base.qcow2 cluster_size=65536 lazy_refcounts=off refcount_bits=16 [root@singularity images]# qemu-img info overlay1.qcow2 image: overlay1.qcow2 file format: qcow2 virtual size: 8.0G (8589934592 bytes) disk size: 17K cluster_size: 65536 backing file: /var/lib/libvirt/images/base.qcow2 Format specific information: compat: 1.1 lazy refcounts: false refcount bits: 16 corrupt: false # try the same with virsh vol-create-as; note how you must specify filesize and the backing file format is *wrong* (leading to an unusable overlay disk) [root@singularity images]# virsh vol-create-as default overlay2.qcow2 8G --format qcow2 --backing-vol /var/lib/libvirt/images/base.qcow2 Vol overlay2.qcow2 created [root@singularity images]# qemu-img info overlay2.qcow2 image: overlay2.qcow2 file format: qcow2 virtual size: 8.0G (8589934592 bytes) disk size: 17K cluster_size: 65536 backing file: /var/lib/libvirt/images/base.qcow2 backing file format: raw Format specific information: compat: 0.10 refcount bits: 16 -- 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] Running all my virtual machines with a low priority
by R. Diez 02 May '19

02 May '19

Hi all: I have an Ubuntu 18.04 system. What is the easiest way to run all of my virtual machines with a low priority? Say a "nice" level of 15. I just do not want my virtual machines to have too much of an impact in any other processes on the system. Thanks in advance, rdiez

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[libvirt-users] Cloning a volume via storage XML
by Weller, Lennart 30 Apr '19

30 Apr '19

Hello everyone, After the Bug with libvirt was found and fixed by Michal I am now looking for a way to actually do the task I intended to do. I cannot find any information if it is possible to clone a base-volume a la vol- clone for ceph rbd. As I posted in my addendum to the first post here I thought something like this volume xml would do the job: <volume> <name>coreos00.disk</name> <capacity unit="bytes">9116319744</capacity> <target> <format type="raw"></format> <permissions> <mode>644</mode> </permissions> </target> <backingStore> <path>vmdisks/coreos_2023</path> <format type="raw"></format> </backingStore> </volume> But even with the fix applied this simply creates an empty volume of the given size. Granted this has no information about the snapshot so I was sceptical that this would be enough in the first place. If the vol-clone is not an option right now via volume xml it's not that wild as I could just patch the terraform-libvirt-provider to do the task beforehand but I wanted to know if it there exists an option for libvirt to do it automatically when provided with an xml. I can't find any options in the storage xml documentation so my guess would be no. Kind regards, Lennart Weller

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[libvirt-users] libvirtd via unix socket using system uri
by lameventanas＠gmail.com 30 Apr '19

30 Apr '19

I want to run libvirtd as a special user, and allowing users that belong to a special group to connect via qemu+unix:///system (eg: unix socket). I did everything necessary to do so: created a libvirt user and group, added the libvirt user to the kvm group, added my normal user to the libvirt group, and made sure the socket is owned by libvirt:libvirt with permissions set to 770. libvirtd starts successfully, but when I try to connect as the normal user I get this error: bash$ virsh --connect qemu+unix://system error: failed to connect to the hypervisor error: invalid argument: using unix socket and remote server 'system' is not supported. A trace shows virsh is not even trying to open the socket. I want to use the socket because I just need local connectivity and don't want to run sasl and set up certificates for this, but at the same time want to run libvirtd as a dedicated user. Is there any reason to prevent libvirt from being used like this?

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[libvirt-users] Error connecting to hypervisor
by Sukrit Bhatnagar 29 Apr '19

29 Apr '19

Hi, I have compiled and installed libvirt from git checkout and started libvirtd service. The version is 5.3.0 and I have done system-wide installation. When I do a `virsh list`, I get the following error: error: failed to connect to the hypervisor error: Unable to encode message header Similarly, the libvirtd instance shows the following error: 2019-04-23 21:36:57.777+0000: 1807: info : libvirt version: 5.3.0 2019-04-23 21:36:57.777+0000: 1807: info : hostname: dell 2019-04-23 21:36:57.777+0000: 1807: error : virNetSocketReadWire:1803 : End of file while reading data: Input/output error Furthermore, virnetmessagetest show the following error: $ VIR_TEST_DEBUG=1 ./virnetmessagetest TEST: virnetmessagetest 1) Message Header Encode ... libvirt: XML-RPC error : Unable to encode message header FAILED 2) Message Header Decode ... libvirt: XML-RPC error : Unable to decode message length FAILED 3) Message Payload Encode ... libvirt: XML-RPC error : Unable to encode message header FAILED 4) Message Payload Decode ... libvirt: XML-RPC error : Unable to decode message length FAILED 5) Message Payload Stream Encode ... libvirt: XML-RPC error : Unable to encode message header FAILED I am also compiling qemu from source and the virsh commands ran fine when I was using libvirt 4.7.0 from Fedora repository. Any ideas how I can solve this issue? Thanks, Sukrit

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