April 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] ceph rbd pool and libvirt manageability (virt-install)
by Jelle de Jong 28 Aug '18

28 Aug '18

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hello everybody, I created a rbd pool and activated it, but I can't seem to create volumes in it with virsh or virt-install? # virsh pool-dumpxml myrbdpool <pool type='rbd'> <name>myrbdpool</name> <uuid>2d786f7a-2df3-4d79-ae60-1535bcf1c6b5</uuid> <capacity unit='bytes'>6997998301184</capacity> <allocation unit='bytes'>10309227031</allocation> <available unit='bytes'>6977204658176</available> <source> <host name='ceph01.powercraft.nl' port='6789'/> <host name='ceph02.powercraft.nl' port='6789'/> <host name='ceph03.powercraft.nl' port='6789'/> <name>libvirt-pool</name> <auth type='ceph' username='libvirt'> <secret uuid='029a334e-ed57-4293-bb99-ffafa8867122'/> </auth> </source> </pool> # virt-install --version 1.0.1 # virsh --version 1.2.9 I ended using virsh edit ceph-test.powercraft.nl and making creating the disk manually. <disk type='network' device='disk'> <auth username='libvirt'> <secret type='ceph' uuid='029a334e-ed57-4293-bb99-ffafa8867122'/> </auth> <source protocol='rbd' name='libvirt-pool/kvm01-storage'> <host name='ceph01.powercraft.nl' port='6789'/> <host name='ceph02.powercraft.nl' port='6789'/> <host name='ceph03.powercraft.nl' port='6789'/> </source> <target dev='vdc' bus='virtio'/> </disk> I use virt-install a lot to define, import and undefine domains, how can I use virt-install to manage my rdb disks? Kind regards, Jelle de Jong -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iJwEAQECAAYFAlV1xlQACgkQ1WclBW9j5HkbPQP+PjNrzvlqysslOp2Yk7wH4Mxy 2sh2dn96G0KOAHEeEn3BN6IWlnD1TADZbHdpTtMwkdv48Xwn0sP1s+3QDM4pb3gP n+z+dVxS8FouDIy/eiso3IBCj3g4TWbEX8ZHqs3jKqe0lZgAXBzB9xYSUowcEBrZ ddkPbr8p8ozWyOG+9V8= =lkK7 -----END PGP SIGNATURE-----

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[libvirt-users] virRandomBits - not very random
by Brian Rak 01 Jun '18

01 Jun '18

I just ran into an issue where I had about 30 guests get duplicate mac addresses assigned. These were scattered across 30 different machines. Some debugging revealed that: 1) All the host machines were restarted within a couple seconds of each other 2) All the host machines had fairly similar libvirtd pids (within ~100 PIDs of each other) 3) Libvirt seeds the RNG using 'time(NULL) ^ getpid()' This perfectly explains why I saw so many duplicate mac addresses. Why is the RNG seed such a predictable value? Surely there has to be a better source of a random seed then the timestamp and the pid? The PID seems to me to be a very bad source of any randomness. I just ran a test across 60 of our hosts. 43 of them shared their PID with at least one other machine.

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[libvirt-users] Create qcow2 v3 volumes via libvirt
by Gionatan Danti 24 May '18

24 May '18

Hi all, on a fully patched CentOS 7.4 x86-64, I see the following behavior: - when creating a new volumes using vol-create-as, the resulting file is a qcow2 version 2 (compat=0.10) file. Example: [root@gdanti-lenovo vmimages]# virsh vol-create-as default zzz.qcow2 8589934592 --format=qcow2 --backing-vol /mnt/vmimages/centos6.img Vol zzz.qcow2 created [root@gdanti-lenovo vmimages]# file zzz.qcow2 zzz.qcow2: QEMU QCOW Image (v2), has backing file (path /mnt/vmimages/centos6.img), 8589934592 bytes [root@gdanti-lenovo vmimages]# qemu-img info zzz.qcow2 image: zzz.qcow2 file format: qcow2 virtual size: 8.0G (8589934592 bytes) disk size: 196K cluster_size: 65536 backing file: /mnt/vmimages/centos6.img backing file format: raw Format specific information: compat: 0.10 refcount bits: 16 - when creating a snapshot, the resulting file is a qcow2 version 3 (comapt=1.1) file. Example: [root@gdanti-lenovo vmimages]# virsh snapshot-create-as centos6left --disk-only --no-metadata snap.qcow2 Domain snapshot snap.qcow2 created [root@gdanti-lenovo vmimages]# file centos6left.snap.qcow2 centos6left.snap.qcow2: QEMU QCOW Image (v3), has backing file (path /mnt/vmimages/centos6left.qcow2), 8589934592 bytes [root@gdanti-lenovo vmimages]# qemu-img info centos6left.snap.qcow2 image: centos6left.snap.qcow2 file format: qcow2 virtual size: 8.0G (8589934592 bytes) disk size: 196K cluster_size: 65536 backing file: /mnt/vmimages/centos6left.qcow2 backing file format: qcow2 Format specific information: compat: 1.1 lazy refcounts: false refcount bits: 16 corrupt: false From what I know, this is a deliberate decision: compat=1.1 requires relatively recent qemu version, and creating a new volume play on the "safe side" of compatibility. It is possible to create a new volume using qcow2 version 3 (compat=1.1) format *using libvirt/virsh* (I know I can do that via qemu-img)? Any drawback on using version 3 format? 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] Unable to detach disk using 'virsh detach-disk'
by Andre Goree 09 May '18

09 May '18

I'm unable to detach a disk from a Windows guest using the 'virsh detach-disk' command. Even though 'domblklist' shows the disk attached, and on the FIRST iteration, it says the command "completed successfully," 'domblklist will still show the disk attached and subsequent 'detach-disk' commands fail with 'no disk found whose source path or target is ${location}' ~ # virsh domblklist 31907-1063435 Target Source ------------------------------------------------ vda ${concatenated}/31907-1063435/2018-04-28-190529 vdb ${concatenated}/31907-67863/2018-03-21-033216.2018-04-28-190529 ~ # virsh detach-disk --domain 31907-1063435 /var/lib/libvirt/images/instances/31907-67863/2018-03-21-033216.2018-04-28-190529 --persistent error: No disk found whose source path or target is /var/lib/libvirt/images/instances/31907-67863/2018-03-21-033216.2018-04-28-190529 Any ideas as to why this happens? -- Andre Goree -=-=-=-=-=- Email - andre at drenet.net Website - http://blog.drenet.net PGP key - http://www.drenet.net/pubkey.html -=-=-=-=-=-

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[libvirt-users] User name / session idin logs
by Anastasiya Ruzhanskaya 07 May '18

07 May '18

Hello everyone, I have a question about logging. I need to find out whether it is possible to see user id/session id inside logs or somewhere else. It is not passed in structured across the network, so where should I look to find out, which user (which session) is currently performing the actions?

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[libvirt-users] connecting host and guest vm using a dummy nic
by daggs 03 May '18

03 May '18

Greetings all, I have a host machine that runs a router within a vm. I want to allow a connection between the host and the guest so the host can connect to the lan provided by the router vm. I've created a dummy interface with these commands: $ ip link add ens99-dummy type dummy $ ip link set ens99-dummy address 52:54:00:1f:d0:ff this resulted with this output: $ ifconfig ens99-dummy ens99-dummy Link encap:Ethernet HWaddr 52:54:00:1F:D0:FF inet6 addr: fe80::84b5:24ff:fe62:c16d/64 Scope:Link UP BROADCAST RUNNING NOARP MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:899 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:0 (0.0 B) TX bytes:321727 (314.1 KiB) in my libvirt's xml file I have this entry: <interface type='direct'> <mac address='52:54:00:0c:cb:3e'/> <source dev='ens99-dummy' mode='private'/> <target dev='macvtap0'/> <model type='e1000'/> <alias name='net0'/> <address type='pci' domain='0x0000' bus='0x02' slot='0x01' function='0x0'/> </interface> after the vm is up, I see the adapter in the vm and the host has one more entry: $ ifconfig macvtap0 macvtap0 Link encap:Ethernet HWaddr 52:54:00:0C:CB:3E inet6 addr: fe80::5054:ff:fe0c:cb3e/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:889 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:500 RX bytes:0 (0.0 B) TX bytes:320523 (313.0 KiB) but when I try to request ip via dhcp from both macvtap0 and ens99-dummy I don't get any. any idea why?

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