November 2014 - Users - libvirt List Archives

[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] Libvirt Live Migration
by Dhia Abbassi 04 Dec '14

04 Dec '14

I'm trying to implement a virtualization API. I was testing migration with libvirt I got some problems. When I use the following command : *virsh migrate --live --persistent --copy-storage-all vm-clone1 qemu+ssh://server_ip/system* the migration works fine but in the destination host the migrated vm is paused and I can't unpause it and I need to reboot the vm to be able use it in the new host. When I try to unoause it Igot the following error message: << *Error unpausing domain: internal error: unable to execute QEMU command 'cont': Resetting the Virtual Machine is required *>> How can I solve this problem, or is there an other way to make a live migration with libvirt?? Thank you for you consideration. -- Best regards *Dhia Abbassi* Full Stack Engineer | Rosafi Holding <http://tn.linkedin.com/in/dhiaabbassi> <https://github.com/DhiaTN> <https://plus.google.com/u/0/+DhiaAbbassi> <https://twitter.com/DhiaTN>

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[libvirt-users] python migrateSetMaxSpeed not taking effect
by Krutskikh Ivan 28 Nov '14

28 Nov '14

Hi, I am writing a simple python script for migrating vm's based on zfs zvol's. Either I am doing something wrong or python migrateSetMaxSpeed not taking effect: no mater what value I specify (except for 0), I end up with 10 Mib/s migration speed. The code is: def virt_migrate(domain): conn = libvirt.open('qemu:///system') domain_obj = conn.lookupByName(domain) dst='qemu+ssh://root@%s/system' % args.remote domain_obj.migrateSetMaxSpeed(40,0) new_dom = domain_obj.migrateToURI(dst,libvirt.VIR_MIGRATE_LIVE | libvirt.VIR_MIGRATE_PEER2PEER | libvirt.VIR_MIGRATE_NON_SHARED_INC | libvirt.VIR_MIGRATE_PERSIST_DEST | libvirt.VIR_MIGRATE_UNDEFINE_SOURCE, None, 0) conn.close() Also tried to specify bandwidth at migrateToUri- I still get 10 mib/s at any value... Thanks in advance!

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[libvirt-users] Live Disk Snapshot Not Supported
by Payes Anand 25 Nov '14

25 Nov '14

# virsh snapshot-create-as small snap1 --disk-only --atomic error: Operation not supported: live disk snapshot not supported with this QEMU binary OS used: CentOS 7 #virsh version Compiled against library: libvirt 1.1.1 Using library: libvirt 1.1.1 Using API: QEMU 1.1.1 Running hypervisor: QEMU 1.5.3 Any help would be greatly appreciated. Best Regards, Payes

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[libvirt-users] how to modify virsh vm start script
by Ady Wahyudi Paundu 25 Nov '14

25 Nov '14

I use libvirt to manage a QEMU/KVM system. Starting a VM only by using > virsh start vmname What I want to know is how to add an option to virsh vm's start script, in my case I want to add QEMU logging option (-d and -D). I can see from > ps aux | grep qemu that current VM started using virsh not including those options ~ady

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[libvirt-users] Libvirt fullscreen sdl problem
by Дориан Грей 25 Nov '14

25 Nov '14

Hi all, I use libvirt/kvm for my virtualization needs and have a little scerio in mind that I want to implement: a small linux box boots up, launches an X session and after that launches a virtual machine with a fullscreen sdl window, With this I hope to achive several goals: user gets a familiar experience with guest os ( I had windows in mind), near native graphics responsiveness ( we deploy cctv video servers and viewing live video in a virt machine is a must) and security based on isolation from i/o ports. But when I tried this scenario with <graphics type='sdl' display=':0.0' xauth='/home/stein/.XAuthority'/> in xml file I got: linux-aeo3:/etc/libvirt/qemu # virsh start wintest setlocale: No such file or directory error: Failed to start domain wintest error: internal error: early end of file from monitor: possible problem: No protocol specified xcb_connection_has_error() returned true pulseaudio: pa_context_connect() failed pulseaudio: Reason: Connection refused pulseaudio: Failed to initialize PA contextaudio: Could not init `pa' audio driver ALSA lib pcm_dmix.c:1022:(snd_pcm_dmix_open) unable to open slave alsa: Could not initialize DAC alsa: Failed to open `default': alsa: Reason: Device or resource busy ALSA lib pcm_dmix.c:1022:(snd_pcm_dmix_open) unable to open slave alsa: Could not initialize DAC alsa: Failed to open `default': alsa: Reason: Device or resource busy audio: Failed to create voice `dac' No protocol specified Could not initialize SDL(No available video device) - exiting Even if I disable audio and get rid of alsa problems, I still get Could not initialize SDL(No available video device) - exiting error. What am I doing wrong? Please not that lauching qemu-kvm with sdl window goes without problems. Thanks in advance!

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[libvirt-users] Put virbr0 in promiscusous
by Sagar Shedge 24 Nov '14

24 Nov '14

Hi , I have two virtual machines VM1 and VM2. Then I have added eth0 of my VM to 'default' network. Use case :- I want to monitor all traffic on virbr0('default' network). Steps followed :- 1. Add VM1 eth0 to virbr0 2. Add VM2 eth1 to virbr0 3. brctl setageing ovsbr0 0 ..(To put bridge in promiscuous) Now I am running tcpdump on eth1 of VM2 and trying to ping google.com(outside world) In VM2 (tcpdump -i eth1), I can see only ingress(incoming) traffic of VM1. I am not able see outgoing traffic of VM1. If I create another bridge and trying same scenario with 2 VM then VM2 can see both ingress and outgress traffic. So want to know what is the issue? Is libvirt doing something different with this virtbr0 bridge? -- Sagar Dilip Shedge, Pune. With Regards.

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[libvirt-users] Error starting domain: internal error: missing IFLA_VF_INFO in netlink response
by Hong-Hua.Yin＠freescale.com 24 Nov '14

24 Nov '14

Hi, We try PCI Passthrough of host network devices on PPC platform. http://wiki.libvirt.org/page/Networking#Assignment_with_.3Cinterface_type.3… But we got a similar issue as below that reported on RedHat before: https://bugzilla.redhat.com/show_bug.cgi?id=1040626 With <hostdev>, it could start VM successfully. <hostdev mode='subsystem' type='pci' managed='yes'> <driver name='vfio'/> <source> <address domain='0x0000' bus='0x01' slot='0x00' function='0x4'/> </source> </hostdev> Logged into VM and checked for VF using lspci root@model : qemu ppce500:~# lspci 00:00.0 PCI bridge: Freescale Semiconductor Inc MPC8533E 00:02.0 Power PC: Freescale Semiconductor Inc Device 0000 (rev 20) 00:03.0 Unclassified device [00ff]: Red Hat, Inc Virtio memory balloon But it will fail if using <interface type="hostdev">: <interface type="hostdev" managed="yes"> <mac address="00:e0:0c:00:20:01"/> <source> <address type="pci" domain="0x0000" bus="0x01" slot="0x00" function="0x4"/> </source> </interface> # virsh create vf.xml 2014-11-24 11:08:31.390+0000: 3556: info : libvirt version: 1.2.2 2014-11-24 11:08:31.390+0000: 3556: debug : virLogParseOutputs:1378 : outputs=1:file:virsh.log error: Failed to create domain from vf.xml error: internal error: missing IFLA_VF_INFO in netlink response Exactly We're using max_vfs=2 and libnl-3.2.22 # ls -l /usr/lib64/libnl-3.so.200.17.0 -rwxr-xr-x 1 root root 154440 Sep 17 07:15 /usr/lib64/libnl-3.so.200.17.0 Why this issue happened on PPC? Is there anything architecture-specific support needed to add? Thanks, Olivia

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Re: [libvirt-users] some problem with snapshot by libvirt
by Payes Anand 21 Nov '14

21 Nov '14

Eric Blake <eblake@...> writes: > > On 05/27/2012 06:39 PM, xingxing gao wrote: > > Hi,all,i am using libvirt to manage my vm,in these days i am testing > > the libvirt snapshot ,but meet some problem: > > > > the snapshot was created from this command: > > snapshot-create-as win7 --disk-only --diskspec > > vda,snapshot=external --diskspec hda,snapshot=no > > > > but when i tried to revert from the snapshot which created from the > > above command ,i got error below: > > > > virsh # snapshot-revert win7 1338041515 --force > > error: unsupported configuration: revert to external disk snapshot not > > supported yet > > Yep. You've run into a case where I haven't yet been able to code > things. The problem is that reverting to a disk image has a question - > you are starting with two files (the snapshot backing file and the new > qcow2 wrapper), but the moment you reload the backing file for > modification, you invalidate the qcow2 wrapper. There are two sane > options - create yet another qcow2 wrapper around the same backing file, > or delete the qcow2 wrapper as part of reverting to the snapshot, but we > would probably need two new flags to the virDomainRevertToSnapshot API > to select one of these two behaviors. In the meantime, the only way to > revert to a disk-only snapshot is to manually edit the domain XML to > match what you want to do, possibly with manual qemu-img operations as well. > > Help in writing the patches to improve the functionality would be welcome. > Has the issue ( revert to external disk snapshot ) been solved in later versions of libvirt? I am using: Compiled against library: libvirt 1.2.2 Using library: libvirt 1.2.2 Using API: QEMU 1.2.2 Running hypervisor: QEMU 2.1.92 On trying to revert to an external snapshot, Getting the error: revert to external disk snapshot not supported yet If not is there any alternate.

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[libvirt-users] some problem with snapshot by libvirt
by xingxing gao 21 Nov '14

21 Nov '14

Hi,all,i am using libvirt to manage my vm,in these days i am testing the libvirt snapshot ,but meet some problem: the snapshot was created from this command: snapshot-create-as win7 --disk-only --diskspec vda,snapshot=external --diskspec hda,snapshot=no but when i tried to revert from the snapshot which created from the above command ,i got error below: virsh # snapshot-revert win7 1338041515 --force error: unsupported configuration: revert to external disk snapshot not supported yet version: virsh # version Compiled against library: libvir 0.9.4 Using library: libvir 0.9.4 Using API: QEMU 0.9.4 Running hypervisor: QEMU 1.0.93

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