October 2016 - Users - libvirt List Archives

[libvirt-users] domain schema fails to validate sysinfo element
by mordenkainen 13 Oct '16

13 Oct '16

I'm puzzled why virt-xml-checker rejects minimal config xml if it includes sysinfo element: <domain type='kvm'> <name>example</name> <sysinfo> </sysinfo> </domain> with the following error: Relax-NG validity error : Extra element sysinfo in interleave minimal.xml:3: element sysinfo: Relax-NG validity error : Element domain failed to validate content minimal.xml fails to validate I tried xmllint it gives the same output

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[libvirt-users] Windows 7 guest not starting with HyperV features enabled
by Aleksei 11 Oct '16

11 Oct '16

Hi, I have a Windows 7 SP1 Pro 64-bit VM which works fine on libvirt 2.3.0 and Qemu 2.7.0. If I enable HyperV features (https://libvirt.org/formatdomain.html#elementsFeatures) like "relaxed", "spinlocks" etc - VM doesn't boot. "Starting Windows" text appears for ~2 seconds (no flying dots, no logo) and then it just goes to black screen. If I switch HyperV features back off, it boots normally again. Running VM with debuggging enabled (virsh --log win7_hyperv.log --debug 1 start win7) doesn't produce any errors in the log. There are no logs for that attempted boot in the guest either - apparently it doesn't get to the point when Windows starts logging. Attaching VM xml definition (with HyperV features enabled). -- /--Regards, Aleksei/

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[libvirt-users] Problems connecting to the libvirtd server
by Stefano Ricci 11 Oct '16

11 Oct '16

Hello everyone I do not know if it is correct address this mailing lists but I can not use libvirt. I run compile libvirt version 2.2.0 into environment lfs stable with qemu 2.7.0 and have not had any problems. The program when it starts not report any errors in the log, with activated debug level file. Only when you try to connect with the following command virsh -c qemu:///system remains hung without reporting any error either in the logs that screen. The command virsh -c test:///default list instead concludes on a regular basis. I attach the file libvirt.log and libvirt.conf Thank you Stefano Ricci

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[libvirt-users] Dealing with swappiness on host systems
by Dennis Jacobfeuerborn 10 Oct '16

10 Oct '16

Hi, I'm looking for a way to prevent qemu processes on a libvirt host to use swap unless there is no physical memory free but apparently this is not as easy as I'd hoped it would be. This is on a CentOS 7 system. At first I tried setting /proc/sys/vm/swappiness to 1 (apparently setting it to 0 now means even the OOM killer takes precedence over swapping: https://www.percona.com/blog/2014/04/28/oom-relation-vm-swappiness0-new-ker… ). After doing this I could still see the used swap increase for a guest even though there were 28G of memory used only as page-cache on the host. Taking another look at it I notices that swappiness can now apparently be controlled on a per-process basis as well by means of using the files under /sys/fs/cgroup/memory/machine.slice however I found no good documentation describing which of the values takes precedence and whether these values can be modified on the fly the same way the files under /proc can. Has anyone pointers to documentation that explains how all of this works? More specifically: Which of these paths take precedence for a running process: /proc/sys/vm/swappiness /sys/fs/cgroup/memory/machine.slice/memory.swappiness /sys/fs/cgroup/memory/machine.slice/<guest-id>/memory.swappiness Can any/all of these values be modified on the fly and if not is there another way to tell qemu to prefer physical memory to swap and only use swap when no physical memory is available? Regards, Dennis

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[libvirt-users] Permission denied for volume create in raw format
by Maciej Nabożny 07 Oct '16

07 Oct '16

Hi, I'm facing similar problem to described here: https://www.redhat.com/archives/libvirt-users/2016-February/msg00033.html I got Libvirt pool mounted over netfs and I'm trying to create new volume, with pool.createXML. When format is qcow2, everything works fine. Unfortunately, for raw images libvirt raises error Permission denied. Whole pool is owned by root. Libvirt starts as root user too. I've tried to change pool's permissions to 777 on filesystem, but i get the same error, only for RAW images. Volume's xml looks like: <volume> <name>{{user.id}}_{{image.id}}</name> <source> </source> <capacity unit='bytes'>{{image.size}}</capacity> <target> <format type='{{ image.format }}'/> <permissions> <mode>660</mode> </permissions> </target> </volume> I've tried to create it without defining permissions, but it's the same. Problem exists in Ubuntu Server 16.04 (libvirt from repo) and Raspbian (libvirt in version 1.2.9). Do you know if it is possible solve this problem with this version of libvirt? -- Maciej Nabożny cloudover.io

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[libvirt-users] Differentiating Disk access from different VMs
by Affan Syed 05 Oct '16

05 Oct '16

All, I have a specific use case where I want to be ale look at vfs or blk_io requests on the host machine and differentiate which VMs the access is originating from. I am assuming a Disk backend, and looking for virsh command or libvirt API that can help me do so. I have tried quite a bit to Google-fu this problem; no such luck. Would love to know if there is some cute trick to do so. Thanks. Affan

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