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[libvirt-users] command reference
by Laszlo Hornyak 09 Dec '14

09 Dec '14

Hi, I have found the online command reference somewhat incomplete so I thought I give it a try and fill in some of the gaps, but when I cloned the repo I noticed that the last commit happened a little more than 3 years ago. Do you guys accept patches for the documentation? What is the plan in general for the future on the documentation front lines? -- EOF

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[libvirt-users] best shared storage solution ?
by Jason Vas Dias 09 Dec '14

09 Dec '14

Good day - Is there a way of safely allowing a guest OS to access a disk storage device that is also mounted at the same time by the hypervisor or another guest ? I have Linux LVM volumes containing ext4 and btrfs filestystems that need to be shared between the hypervisor and the guests, and between guests . Attempts to use NFS are too slow to be useable - it takes a guest around 4 hours to uncompress and extract a 10MB tar file (using 4 2.9GHz cores). I need access to the shared file system at all times to use as my /home directory from the hypervisor host, so I guess this rules out iSCSI . I came accross documentation on 'sanlock', but its purpose seems to be antithetical to what I require, as described at: http://libvirt.org/locking.html : " how to ensure a single disk cannot be used by more than one running VM at a time, across any host in a network" - but I want to ensure SAFE concurrent access by multiple VMs or any kernel , either on the hypervisor hardware or in a VM guest, to the same filesystems ( ext4, btrfs ) on the same machine, without having to use a network file system . Can sanlock be used to accomplish this ? Or is there any other method that allows the same filesystem to be safely accessed by more than one kernel running on the same host ? The libvirt documentation is very sketchy on this subject, but I understand that just using the '<shareable/>' in the VM configuration XML is not enough, and a lock manager must be configured - can sanlock be used for this, or is there another lock manager that can ? Thanks & Regards, Jason Vas Dias

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[libvirt-users] Libvirt Live Migration
by Dhia Abbassi 05 Dec '14

05 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] Problem with /dev/tty in LXC established with virt-install
by Vegard Vesterheim 05 Dec '14

05 Dec '14

I have created a LXC container with debootstrap followed by virt-install like this: host=mylxc1 debootstrap wheezy /home/lxc/$host virt-install -c lxc:// -n $host --filesystem /home/lxc/$host,/ --ram 1024 I am confused about the /dev filesystem in this container. Specifically the device '/dev/tty'. >From inside the container: ~# ls -la /dev/tty ls: cannot access /dev/tty: No such file or directory # mknod -m 666 /dev/tty c 4 0 mknod: `/dev/tty': Operation not permitted A LXC container created and started with the native LXC commands (lxc-create/lxc-start) has a functioning /dev/tty: # cat </dev/tty foo foo ^C How can I create a functioning /dev/tty with the LXC driver in libvirt? - Vegard V -

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[libvirt-users] Libvirt building fails after download from git
by Pavel Khrulev 04 Dec '14

04 Dec '14

Hello. I need to build libvirt-1.2.10 (with mingw fix) in mingw in windows. I did autogen in linux mint 16, then transferred all files from libvirt directory (sources, configure, makefile.in, ... ) to windows xp. Libvirt is successfully builded in mingw in winxp. Ok. I uploaded all libvirt files (that were successfully builded) to git repository from linux. Then I cloning git rep to windows. And when I do configure, then config.h is not the same with config.h, which is created earlier (before git). And due to this config.h, building libvirt is failed. All files (before upload and arter download ) are the same (checked by KDiff). Do you know, what a problem? May be the problem is in timestamps. (But I tried to touch all files) Or some reconfigure after git. I really dont know. Pavel Khrulev

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[libvirt-users] serial connection between two guests
by Jd 02 Dec '14

02 Dec '14

Hi Is it possible to drive a serial connection between two guests ? For example, the virt-io serial channel used by guestfsd. Can it be driven by virt-io serial connection from another VM ? How do you attach the same device on host as server in one VM and client as another ? Any details on how to go about doing this ? Thanks /Jd

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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 26 Nov '14

26 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 26 Nov '14

26 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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