July 2020 - Users - libvirt List Archives

[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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Set hostname of guest during installation time
by john doe 05 Nov '20

05 Nov '20

Hi, I would like to set the hostname when installing a guest, with the below command the hostname is not set to 'try06' in the guest: virt-install --name=try06 --graphic none --pxe --network bridge=virbr0 How can I set the hostname of the guest during installation time? I realy appriciate the support I'm getting in here, I'm fairly new to libvirt. -- John Doe

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[libvirt-users] Live migrate + change interface name
by Marc Roos 07 Oct '20

07 Oct '20

Is it possible to do a live migrate of a guest, having on the from host a source_device=eth2 and to host a source_dev=eth1?

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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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Two questions about NVDIMM devices
by Milan Zamazal 14 Sep '20

14 Sep '20

Hi, I've met two situations with NVDIMM support in libvirt where I'm not sure all the parties (libvirt & I) do the things correctly. The first problem is with memory alignment and size changes. In addition to the size changes applied to NVDIMMs by QEMU, libvirt also makes some NVDIMM size changes for better alignments, in qemuDomainMemoryDeviceAlignSize. This can lead to the size being rounded up, exceeding the size of the backing device and QEMU failing to start the VM for that reason (I've experienced that actually). I work with emulated NVDIMM devices, not a bare metal hardware, so one might argue that in practice the device sizes should already be aligned, but I'm not sure it must be always the case considering labels or whatever else the user decides to set up. And I still don't feel very comfortable that I have to count with two internal size adjustments (libvirt & QEMU) to the `size' value I specify, with the ultimate goal of getting the VM started and having the NVDIMM aligned properly to make (non-NVDIMM) memory hot plug working. Is the size alignment performed by libvirt, especially rounding up, completely correct for NVDIMMs? The second problem is that a VM fails to start with a backing NVDIMM in devdax mode due to SELinux preventing access to the /dev/dax* device (it doesn't happen with any other NVDIMM modes). Who should be responsible for handling the SELinux label appropriately in that case? libvirt, the system administrator, anybody else? Using <seclabel> in NVDIMM's source doesn't seem to be accepted by the domain XML schema. Thanks, Milan

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Problem with xen config
by Christoph 14 Aug '20

14 Aug '20

Hi all, I 've such a config on xen (4.14): name = "marax.chao5.int" uuid = "e0de3cb7-3937-417d-8d63-b0993b377b6a" maxmem = 16384 memory = 16384 kernel = '/usr/lib64/xen/boot/hvmloader' vcpus = 16 rtc_timeoffset = 0 localtime = 1 on_poweroff = "destroy" on_reboot = "restart" on_crash = "restart" vif = [ "mac=00:16:3e:05:01:10,bridge=xenbr5,script=vif-bridge,model=e1000" ] parallel = "none" serial = "none" type = "hvm" loader = "/usr/lib64/xen/boot/hvmloader" disk = [ "phy:/dev/mapper/marax_c,hda,rw", "phy:/dev/vg_lilith/lv_marax_d,hdb,rw" ] max_grant_frames = "128" pci = [ "01:00.0", "01:00.1", "01:00.2", "01:00.3", "00:1f.3", "05:00.0" ] pci_permissive = 1 keymap = "de" vnclisten="0.0.0.0" pci_power_mgmt=1 xen_platform_pci=1 pci_msitranslate=1 viridian=1 hpet=1 acpi=1 apic=1 pae=1 I want to convert it to a xml format for use it with libvirt/virsh but I get an error: "error: An error occurred, but the cause is unknown" If I comment out the line with pci = [ "01:00.0", "01:00.1", "01:00.2", "01:00.3", "00:1f.3", "05:00.0" ] then it works but I dont see the settings like xen_platform_pci=1 pci_msitranslate=1 pci_permissive = 1 max_grant_frames = "128 and the pci passthrough devices are not there... Does libvirt doesnt support such a config? -- ------ Greetz

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guest-fsfreeze-freeze freezes all mounted block devices
by Marc Roos 09 Aug '20

09 Aug '20

I wondered if anyone here can confirm that virsh qemu-agent-command domain '{"execute":"guest-fsfreeze-freeze"}' Freezes all mounted block devices filesystems. So if I use 4 block devices they are all frozen for snapshotting. Or just the root fs?

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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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Cannot pass secret id for backing file after taking external snapshot on encrypted qcow2 file
by yaohua.wu＠zstack.io 03 Aug '20

03 Aug '20

Hi， I used 'virsh snapshot-create' create an encrypted external snapshot, when I try to use 'qemu-img check' top file, found no entrance to pass backing-file's secret-id 1、Version centos-release-8.2-2.2004.0.1.el8.x86_64 libvirt.x86_64 6.0.0-17.el8 qemu-kvm.x86_64 15:4.2.0-19.el82、Reproduce Steps 1)Create an encrypted qcow2 qemu-img create --object secret,id=sec0,data=123456 -f qcow2 -o encrypt.format=luks,encrypt.key-secret=sec0 first.qcow2 1G 2)Create external snapshot with 'encrypted' xml # cat snap.xml <domainsnapshot> <disks> <disk name='hdc' snapshot='no'/> <disk name='vdb' snapshot='external'> <source file='/root/first-snapshot.qcow2'> <encryption format='luks'> <secret type='passphrase' uuid='f52a81b2-424e-490c-823d-6bd4235bc572'/> </encryption> </source> </disk> </disks> </domainsnapshot> # virsh dumpxml test-vm | awk '/<disk/,/<\/disk/' <disk type='file' device='disk'> <driver name='qemu' type='qcow2'/> <source file='/root/first-snapshot.qcow2' index='5'/> <backingStore type='file' index='2'> <format type='qcow2'/> <source file='/root/first.qcow2'> <encryption format='luks'> <secret type='passphrase' uuid='f981dd17-143f-45bc-88e6-222222222222'/> </encryption> </source> <backingStore/> </backingStore> <target dev='vdb' bus='virtio'/> <encryption format='luks'> <secret type='passphrase' uuid='f52a81b2-424e-490c-823d-6bd4235bc572'/> </encryption> <alias name='virtio-disk1'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x0a' function='0x0'/> </disk> 3)try to qemu-img check top qcow2 file Note: The secid of the backing file is not recorded, so when I use qemu-img check/etc.. how to pass the secret to qemu of backing files # qemu-img info -U first-snapshot.qcow2 image: first-snapshot.qcow2 file format: qcow2 virtual size: 1 GiB (1073741824 bytes) disk size: 544 KiB encrypted: yes cluster_size: 65536 backing file: /root/first.qcow2 ### backing file: json:{"encrypt.format": "luks", "encrypt.key-secret": "secrete-id"} backing file format: luks Format specific information: compat: 1.1 lazy refcounts: false refcount bits: 16 encrypt: ivgen alg: plain64 hash alg: sha256 cipher alg: aes-256 uuid: e4158089-26e4-433f-990e-1d1d0723feee format: luks cipher mode: xts slots: [0]: active: true iters: 1257888 key offset: 4096 stripes: 4000 [1]: active: false key offset: 262144 [2]: active: false key offset: 520192 [3]: active: false key offset: 778240 [4]: active: false key offset: 1036288 [5]: active: false key offset: 1294336 [6]: active: false key offset: 1552384 [7]: active: false key offset: 1810432 payload offset: 2068480 master key iters: 300073 corrupt: false # qemu-img check -U --object secret,id=sec_1,file=/etc/libvirt/secrets/f52a81b2-424e-490c-823d-6bd4235bc572.base64,format=base64 --image-opts encrypt.format=luks,encrypt.key-secret=sec_1,file.filename=first-snapshot.qcow2 --object secret,id=sec_2,file=/etc/libvirt/secrets/f981dd17-143f-45bc-88e6-222222222222.base64,format=base64 qemu-img: Could not open 'encrypt.format=luks,encrypt.key-secret=sec_1,file.filename=first-snapshot.qcow2': Could not open backing file: Parameter 'key-secret' is required for cipher yaohua.wu(a)zstack.io

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libvirt segfaults with "internal,error: Missing monitor reply object", during block live-migration
by Alex Walender 31 Jul '20

31 Jul '20

Dear libvirt community, Using recent Ubuntu Stein Cloud Packages, we are observing random libvirtd live-migration crashes on the target host. Libvirt is having a SEGFAULT with the qemu driver. Transferring block devices usually works without issues. However, the following memory transfer is causing the target libvirtd randomly to close down its socket, resulting in a roll-backed migration process.I can reproduce this with large VMs, which have a large memory pool. The last error message we see in libvirt logs is: error : qemuMonitorJSONCommandWithFd:315 : internal error: Missing monitor reply object With this, libvirt segfaults and restarts. Before we encountered this issue, we used an older nova-compute package (19.0.3). Not sure if this made a difference with usage of libvirtd-api. After upgrade, we also see a lot of recurring errors during migration: warning : qemuDomainObjBeginJobInternal:7044 : Cannot start job (query, none, none) for domain instance-00008f56; current job is (none, none, migration in) owned by (0 <null>, 0 <null>, 0 remoteDispatchDomainMigratePrepare3Params (flags=0x809b)) for (0s, 0s, 14834s) error : qemuDomainObjBeginJobInternal:7066 : Timed out during operation: cannot acquire state change lock (held by monitor=remoteDispatchDomainMigratePrepare3Params) They don't abort the running migration process, but spam every minute to the systemd journal. Source and destination run the same packages: Ubuntu 18.04.4 LTS (GNU/Linux 4.15.0-99-generic x86_64) OpenStack Stein (Ubuntu Cloud Archive) Libvirt+QEMU_x86 keystone-common 2:15.0.1-0ubuntu1~cloud0 libvirt-daemon 5.0.0-1ubuntu2.6~cloud0 qemu-system-x86 1:3.1+dfsg-2ubuntu3.7~cloud0 neutron-linuxbridge-agent 2:14.2.0-0ubuntu1~cloud0 neutron-plugin-ml2 2:14.2.0-0ubuntu1~cloud0 nova-compute 2:19.2.0-0ubuntu1~cloud0 nova-compute-libvirt 2:19.2.0-0ubuntu1~cloud0 I have attached source/destination debug logs from libvirtd and nova-compute here: https://denzelx.ddns.net/index.php/s/KPJ7vv4aTcb69XD Any help would be nice! Best Regards -- M.Sc Alex Walender de.NBI Cloud Bielefeld Administrator Center for Biotechnology (CeBiTec) University of Bielefeld 33594 Bielefeld Germany room: M3-118 phone: +49 (521) 106 2907

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