April 2017 - Users - libvirt List Archives

[libvirt-users] Performance monotoring: Perf Event support
by Hui Jing 26 Apr '17

26 Apr '17

Hi everyone, I am using libvirt 2.5.0. I'd like to enable the "perf events" to monitoring my vm performance such as l3 cache. But it failed with "error: argument unsupported: unable to enable host cpu perf event for cmt". 1. Could you please give some hints on how to check if my host CPU supports cmt,mbm, is it displayed in /proc/cpuinfo? 2. Does the kernel version matters as well to support it? Thanks, Hui

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[libvirt-users] External snapshot issue
by Leroy Tennison 24 Apr '17

24 Apr '17

I have used virsh snapshot-create-as <VM name> <snapshot name> "<snapshot description>" --diskspec "vda,snapshot=external,file=/path/to/external-snapshot" --disk-only --atomic to create an external snapshot of a running VM. I followed it with virsh blockpull <VM name> --path /path/to/external-snapshot and monitored it until done. I confirmed it with qemu-img info /path/to/external-snapshot which shows no backing store. However, when I do grep {/etc,/run}/libvirt/qemu/<VM name>.xml the xml for the VM still shows a backing store in the /run/... definition (but not in the /etc/... definition, my understanding is that the /etc/... definition won't be updated until the VM is shut down): <disk type='file' device='disk'> <driver name='qemu' type='qcow2'/> <source file='/var/lib/libvirt/images/external-snapshot.qcow2'/> <backingStore type='file' index='1'> <format type='qcow2'/> <source file='/var/lib/libvirt/images/original-image-file.qcow'/> <backingStore/> </backingStore> <target dev='hda' bus='ide'/> <alias name='ide0-0-0'/> <address type='drive' controller='0' bus='0' target='0' unit='0'/> </disk> This is using libvirtd version 1.3.1 and qemu-img version 2.5.0. How do I resolve this situation? I don't want to have to rely on a backing store permanently. Thanks for any help or pointers.

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[libvirt-users] ZFS: creating a pool in a created zfs does not work, only when using the whole zfs-pool.
by Thies C. Arntzen 24 Apr '17

24 Apr '17

Hi, I’m new here so apologies if this has been answered before. I have a box that uses ZFS for everything (ubuntu 17.04) and I want to create a libvirt pool on that. My ZFS pool is named „big" So i do: > zfs create big/zpool > virsh pool-define-as --name zpool --source-name big/zpool --type zfs > virsh pool-start zpool > virsh pool-autostart zpool > virsh pool-list > virsh vol-create-as --pool zpool --name test1 --capacity 1G > virsh vol-list zpool Everything seems to work (no error message, vol-list shows the created volume, I can see the volume via zfs list -t all). -BUT- I cannot use that volume via virt-manager and after a short while it’s no longer listed via virsh vol-list zpool. The very same thing works as expected if I create a new zfs pool which I hand into libvirt. So instead of creating a pool from "big/zpool“ I create a pool names „somepool“ on a free device and -voila- everything works. Hope I did make myself clear? Best regards, thies

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[libvirt-users] virt-manager, Network Manager and bridged networking
by Daniel Pocock 24 Apr '17

24 Apr '17

The wiki suggests that Network Manager doesn't support bridges[1] but I think that is out-of-date. Other documents like this[2] show how to set up bridges in Network Manager. For users wanting to run libvirt/KVM on their desktop system, can they now configure a bridge through Network Manager and then use it in virt-manager to create a guest without editing any of their configuration files by hand? Would it be possible for virsh or virt-manager to be enhanced to go one step further and automatically create bridges in Network Manager (using some API) on demand so the user doesn't have to do anything outside of virt-manager? Regards, Daniel 1. https://wiki.libvirt.org/page/Networking#Fedora.2FRHEL_Bridging 2. http://ask.xmodulo.com/configure-linux-bridge-network-manager-ubuntu.html

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[libvirt-users] External snapshot issue addendum
by Leroy Tennison 23 Apr '17

23 Apr '17

I made a mistake in my original post, --diskspec in snapshot-create-as should have shown "hda ...". I also just noticed that 'virsh edit <VM name>' has the correct information (no backing store, only the external snapshot file shown), I was under the impression that /run/... showed the current state, incorrect?

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[libvirt-users] Proper way to remove a qemu-nbd-mounted volume usnig lvm
by Leroy Tennison 23 Apr '17

23 Apr '17

I either haven't searched for the right thing or the web doesn't contain the answer. I have used the following to mount an image and now I need to know the proper way to reverse the process. qemu-nbd -c /dev/nbd0 <qcow2 image using lvm> vgscan --cache (had to use --cache to get the qemu-nbd volume to be recognized, lvmetad is running) vgchange -ay lvdisplay mount <selected qemu-nbd related 'LV Path' found from lvdisplay above> <mount point> I have done the following: umount <mount point> lvchange -an <all qemu-nbd related 'LV Path's found from lvdisplay above> vgchange -an <qemu-nbd related volume> Now what? How do I get the volume out of the list so I can use 'qemu-nbd -d /dev/nbd0' to dis-associate the image with /dev/nbd0? vgreduce seems to be for volumes which have multiple underlying devices. I started to use vgremove but, when it started prompting for confirmation about removing logical volumes, I wasn't sure exactly what it was going to do and responded 'no'. If there is a web reference explaining this specific situation just point me to it - I'm not opposed to reading. Thanks for the help.

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[libvirt-users] subscribe to domain start/stop/panic events
by Vasiliy Tolstov 22 Apr '17

22 Apr '17

Hi! How can i'm subscribe in my app to domain lifecycle messages? Does it possible to subscribe for all domains and not just one? -- Vasiliy Tolstov, e-mail: v.tolstov(a)selfip.ru

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[libvirt-users] libvirtd segfault when using oVirt 4.1 with graphic console - CentOS7.3
by Rafał Wojciechowski 21 Apr '17

21 Apr '17

hello, I am getting such error: libvirtd[27218]: segfault at 0 ip 00007f4940725721 sp 00007f4930711740 error 4 in libvirt.so.0.2000.0[7f4940678000+353000] when I am trying to start VM with graphic spice/vnc console - in headless mode(without graphic console) it is running I noticed this after update oVirt 4.0 to oVirt 4.1 however I noticed that also libvirtd and related packages were upgraded from 1.2.7 to 2.0.0: libvirt-daemon-kvm-2.0.0-10.el7_3.5.x86_64 libvirt-daemon-driver-qemu-2.0.0-10.el7_3.5.x86_64 I am running up to date CentOS7.3 with 3.10.0-514.16.1.el7.x86_64 I have same issue with SELinux and without SELinux(checked after reboot with permissive mode) I tried to get information about this issue from oVirt team, but after mail conversation both me and oVirt team thinks that it might be issue in libvirtd in below link I am putting xmls generated by vdsm which are passing to the libvirtd to run the VMs first one is from vdsm log and second one is extracted from dump after segfault of libvirtd https://paste.fedoraproject.org/paste/eqpe8Byu2l-3SRdXc6LTLl5M1UNdIGYhyRLiv… Regards, Rafal Wojciechowski

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[libvirt-users] libvirt remote connection
by Anastasiya Ruzhanskaya 21 Apr '17

21 Apr '17

Hello, I have some questions about libvirt remote connection. Am I right that internally libvirt uses only tcp ( ssh and tls are only encryption based on this) + ftp ( when working with image itself)? Also I have found that it uses RPC. However, as I know RPC runs above tcp but I cannot capture these packets with wireshark when I am connecting remotely to the host with vm? Is it somehow possible to find out, what data, what messages, in what format are send from my server to the remote libvirt (daemon I suppose?)?

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[libvirt-users] understanding --idmap for containers (v2.5.0)
by mailing lists 20 Apr '17

20 Apr '17

Hello, I'm testing containers on a host machine without selinux so I'm trying use the idmap feature, but I must be missing something because all that I get is a readonly container for the root user. # virsh version --daemon Compiled against library: libvirt 2.5.0 Using library: libvirt 2.5.0 Using API: QEMU 2.5.0 Running hypervisor: QEMU 2.8.1 Running against daemon: 2.5.0 # virsh --connect lxc:/// dumpxml lab-gentoo-01 <domain type='lxc'> <name>lab-gentoo-01</name> <uuid>a9f73091-b716-4b61-95ad-fa1d0c061bef</uuid> <memory unit='KiB'>524288</memory> <currentMemory unit='KiB'>524288</currentMemory> <vcpu placement='static'>2</vcpu> <resource> <partition>/machine</partition> </resource> <os> <type arch='x86_64'>exe</type> <init>/bin/sh</init> </os> <idmap> <uid start='0' target='900' count='10'/> <gid start='0' target='900' count='10'/> </idmap> <features> <privnet/> </features> <cpu mode='host-model'> <model fallback='allow'/> </cpu> <clock offset='utc'/> <on_poweroff>destroy</on_poweroff> <on_reboot>restart</on_reboot> <on_crash>destroy</on_crash> <devices> <emulator>/usr/libexec/libvirt_lxc</emulator> <filesystem type='mount' accessmode='passthrough'> <source dir='/media/containers/lab-gentoo-01/'/> <target dir='/'/> </filesystem> <interface type='bridge'> <mac address='00:16:3e:c8:13:14'/> <source bridge='bridge-01'/> </interface> <console type='pty'> <target type='lxc' port='0'/> </console> </devices> </domain> # ls -l /media/containers/lab-gentoo-01/ total 36 drwxr-xr-x 2 root root 4096 Apr 13 07:33 bin drwxr-xr-x 2 root root 18 Apr 13 03:28 boot drwxr-xr-x 7 root root 4096 Apr 18 12:45 dev drwxr-xr-x 31 root root 4096 Apr 18 12:49 etc drwxr-xr-x 2 root root 18 Apr 13 03:28 home lrwxrwxrwx 1 root root 5 Apr 13 06:13 lib -> lib64 drwxr-xr-x 2 root root 4096 Apr 13 06:14 lib32 drwxr-xr-x 9 root root 4096 Apr 13 07:33 lib64 drwxr-xr-x 2 root root 18 Apr 13 03:28 media drwxr-xr-x 2 root root 18 Apr 13 03:28 mnt drwxr-xr-x 2 root root 18 Apr 13 03:28 opt drwxr-xr-x 2 root root 6 Apr 13 03:18 proc drwx------ 2 root root 18 Apr 13 03:28 root drwxr-xr-x 2 root root 31 Apr 13 07:32 run drwxr-xr-x 2 root root 4096 Apr 13 07:36 sbin drwxr-xr-x 2 root root 18 Apr 13 03:28 sys drwxrwxrwt 2 root root 18 Apr 13 07:36 tmp drwxr-xr-x 13 root root 4096 Apr 18 12:49 usr drwxr-xr-x 9 root root 102 Apr 13 03:28 var # virsh --connect lxc:/// start --console lab-gentoo-01 Domain lab-gentoo-01 started Connected to domain lab-gentoo-01 Escape character is ^] sh-4.3# /usr/bin/id uid=0(root) gid=0(root) groups=0(root) sh-4.3# pwd / sh-4.3# touch asdf touch: cannot touch 'asdf': Permission denied sh-4.3# indeed the container is using the idmap feature because the efective uid/gid map (900/900) is not allowing writes in the filesystem, but it doesn't seems very usefull. is it possible to have read/write containers while using idmap?

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