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[libvirt-users] Update on-disk XML after virsh snapshot-create-as
by Andrew Martin 15 Apr '15

15 Apr '15

Hello, I am using "virsh snapshot-create-as" to create external snapshots of running VMs using libvirt 1.0.2 on Ubuntu 12.04 and libvirt 1.2.2 on Ubuntu 14.04. This works well for creating the snapshots, but I notice that the on-disk XML file in /etc/libvirt/qemu is not updated with the new disk image file after the snapshot is created. This appears to be very similar to https://bugs.launchpad.net/ubuntu/+source/libvirt/+bug/1403841, but occurs on both 12.04 and 14.04 so I am not sure it is the same bug. This presents a problem if the virtual machine host is suddenly powered off since a subsequent boot will find the VM using an older image file to boot rather than the most recent snapshot. Is it safe for me to use an external wrapper script that does the following to ensure the on-disk XML is up-to-date: virsh snapshot-create-as .... virsh dumpxml > /etc/libvirt/qemu/<domain>.xml Is it safe for me to overwrite the contents of /etc/libvirt/qemu/<domain>.xml manually while the VM is running? Thanks, Andrew Martin

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[libvirt-users] How to burn a CD using libvirt?
by Steve Ross 14 Apr '15

14 Apr '15

Hi, My first e-mail... my apologies if this is not the appropriate e-mail list. My goal is to *write* from the guest OS to a CD or DVD reader/writer on my host system. Currently, the write operation is failing. I believe it is because the virtual CD-ROM device is set to be "readonly". Is it possible to write to a QEMU CDROM device and, if so, how? (The host machine's CD-ROM drive does support writing/burning.) I'm using the "virt-manager" GUI to start the virtual machine. Once started, the "qemu" command line from my virtual machine process includes the following, where the host's built-in CD reader/writer is "/dev/sr0". /usr/bin/qemu-system-x86_64 ... -drive file=/dev/sr0,if=none,id=drive-ide0-0-1,readonly=on,format=raw This obviously says that the device is "readonly". A snippet of XML from my virtual machine from the CDROM is: <domain type='kvm'> ... <devices> <disk type='block' device='cdrom'> <driver name='qemu' type='raw'/> <source dev='/dev/sr0'/> <target dev='hdb' bus='ide'/> <readonly/> <address type='drive' controller='0' bus='0' target='0' unit='1'/> </disk> I've tried removing the <readonly/> tag from the above VM definition, and then running the VM, but the tag magically reappears in the VM definition when it runs. Also, the "virt-manager" GUI shows the CDROM device as having the option of "Readonly" being checked (and the GUI does not allow me to uncheck it.) Other details: * qemu version 2.1.3 on Fedora 21. * libvirt version 1.2.0.2 Thanks for any help or pointers you can provide, -- Steve

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[libvirt-users] XML Parser failing due to cryptic Serial Number.
by Roz Fx 14 Apr '15

14 Apr '15

I set virt-manager in qemu:///system space and tried to add new VM but it didn't proceed. Found out serial in crypic form. # cat /sys/devices/virtual/dmi/id/product_serial ÿÿÿÿÿÿÿ #virt-manager --debugTraceback (most recent call last): File "/usr/share/virt-manager/virtManager/libvirtobject.py", line 225, in _reparse_xml self._xmlobj = self._build_xmlobj(self._get_raw_xml()) File "/usr/share/virt-manager/virtManager/libvirtobject.py", line 228, in _build_xmlobj return self._parseclass(self.conn.get_backend(), parsexml=xml) File "/usr/share/virt-manager/virtManager/nodedev.py", line 27, in _parse_convert return NodeDevice.parse(conn, parsexml) File "/usr/share/virt-manager/virtinst/nodedev.py", line 95, in parse tmpdev = NodeDevice(conn, parsexml=xml, allow_node_instantiate=True) File "/usr/share/virt-manager/virtinst/nodedev.py", line 106, in __init__ XMLBuilder.__init__(self, *args, **kwargs) File "/usr/share/virt-manager/virtinst/xmlbuilder.py", line 777, in __init__ parent_xpath, relative_object_xpath) File "/usr/share/virt-manager/virtinst/xmlbuilder.py", line 679, in __init__ self._parse(parsexml, parsexmlnode) File "/usr/share/virt-manager/virtinst/xmlbuilder.py", line 692, in _parse doc = libxml2.parseDoc(xml) File "/usr/lib/python2.7/site-packages/libxml2.py", line 1327, in parseDoc if ret is None:raise parserError('xmlParseDoc() failed') libxml2.parserError: xmlParseDoc() failed [Sun, 12 Apr 2015 06:06:16 virt-manager 4241] DEBUG (create:165) Showing new vm wizard [Sun, 12 Apr 2015 06:06:16 virt-manager 4241] DEBUG (create:892) Guest type set to os_type=hvm, arch=x86_64, dom_type=kvm [Sun, 12 Apr 2015 06:06:16 virt-manager 4241] DEBUG (xmlbuilder:694) Error parsing xml= <device> <name>computer</name> <capability type='system'> <product>Vostro</product> <hardware> <vendor>Dell Inc.</vendor> <version>A10</version> <serial>ÿÿÿÿÿÿÿ</serial> <uuid>REMOVED</uuid> </hardware> <firmware> <vendor>Dell Inc.</vendor> <version>A10</version> <release_date>05/18/2013</release_date> </firmware> </capability> </device> [Sun, 12 Apr 2015 06:06:16 virt-manager 4241] ERROR (create:346) Error setting create wizard conn state. Traceback (most recent call last): File "/usr/share/virt-manager/virtManager/create.py", line 344, in reset_state self.set_conn(activeconn, force_validate=True) File "/usr/share/virt-manager/virtManager/create.py", line 225, in set_conn self.set_conn_state() File "/usr/share/virt-manager/virtManager/create.py", line 626, in set_conn_state self.netlist.reset_state() File "/usr/share/virt-manager/virtManager/netlist.py", line 405, in reset_state self._populate_network_list() File "/usr/share/virt-manager/virtManager/netlist.py", line 253, in _populate_network_list vnet_bridges) File "/usr/share/virt-manager/virtManager/netlist.py", line 185, in _find_physical_devices for nodedev in self.conn.get_nodedevs("net"): File "/usr/share/virt-manager/virtManager/connection.py", line 648, in get_nodedevs xmlobj = dev.get_xmlobj() File "/usr/share/virt-manager/virtManager/libvirtobject.py", line 160, in get_xmlobj self._reparse_xml() File "/usr/share/virt-manager/virtManager/libvirtobject.py", line 225, in _reparse_xml self._xmlobj = self._build_xmlobj(self._get_raw_xml()) File "/usr/share/virt-manager/virtManager/libvirtobject.py", line 228, in _build_xmlobj return self._parseclass(self.conn.get_backend(), parsexml=xml) File "/usr/share/virt-manager/virtManager/nodedev.py", line 27, in _parse_convert return NodeDevice.parse(conn, parsexml) File "/usr/share/virt-manager/virtinst/nodedev.py", line 95, in parse tmpdev = NodeDevice(conn, parsexml=xml, allow_node_instantiate=True) File "/usr/share/virt-manager/virtinst/nodedev.py", line 106, in __init__ XMLBuilder.__init__(self, *args, **kwargs) File "/usr/share/virt-manager/virtinst/xmlbuilder.py", line 777, in __init__ parent_xpath, relative_object_xpath) File "/usr/share/virt-manager/virtinst/xmlbuilder.py", line 679, in __init__ self._parse(parsexml, parsexmlnode) File "/usr/share/virt-manager/virtinst/xmlbuilder.py", line 692, in _parse doc = libxml2.parseDoc(xml) File "/usr/lib/python2.7/site-packages/libxml2.py", line 1327, in parseDoc if ret is None:raise parserError('xmlParseDoc() failed') parserError: xmlParseDoc() failed Any help will appreciate. RegardsRox

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[libvirt-users] libvirt vs PCI virtio
by Pavel Fedin 14 Apr '15

14 Apr '15

Hello! I am working on vhost-net support for ARM and want to try to set up complete configuration with irqfds. For this purpose i need to change address type specification for this device from "virtio-mmio" to "PCI". But, when i attempt to do so, i get error message "No PCI buses available". Can anybody explain me what i am doing wrong ? The most confusing part is that i use 'virt' machine which actually has generic PCI host, and for test purposes i even set up SATA controller for my virtual machine which perfectly appears on the emulated bus. And specification for SATA is simply: --- cut --- <controller type='sata' index='0'/> --- cut --- without any explicit PCI location specifiers. Kind regards, Pavel Fedin Expert Engineer Samsung Electronics Research center Russia

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[libvirt-users] Installing virtio drivers on a windows guest
by Jeff Tchang 14 Apr '15

14 Apr '15

Just thought I would share my experience trying to get the virtio windows drivers loaded. I kept using the wrong ones and getting a blue screen until I realized I needed to use my distribution's virtio packages. Wrote up a quick article: http://www.returnbooleantrue.com/2015/04/making-your-windows-kvm-guest-boxe…

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[libvirt-users] Passing environment variables to LXC container
by Harish Vishwanath 13 Apr '15

13 Apr '15

Hello I am looking for options to pass some ENV variables to an LXC container managed by libvirt. Is it possible to do so from the XML file itself? Something along the lines of qemu command line options? Regards, Harish

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[libvirt-users] CPU Resource Reservation using KVM
by Jatin Davey 13 Apr '15

13 Apr '15

Hi All I am new to KVM world. I have been using VMware for about a year. In VMware world we can reserve cpu resources for a VM. Say for instance if we need 4 vCPUs with a total of 8000 GHz then we can mention this configuration in vCenter while creating a VM. This guarantees 8000 GHz of cpu resources for the deployed VM. How can i achieve the same thing using KVM ? Please provide as much details as possible. Any pointers for reading this would also be helpful. Appreciate your responses in this regard. Thanks Jatin

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[libvirt-users] issue on fedora21 with libvirt-1.2.13 and 1.2.14 - containers won't start at all
by Thierry Parmentelat 11 Apr '15

11 Apr '15

Answering my own question, seems like my problem is very similar to what is reported below for redhat enterprise linux 7 https://bugzilla.redhat.com/show_bug.cgi?id=1209757

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[libvirt-users] issue on fedora21 with libvirt-1.2.13 and 1.2.14 - containers won't start at all
by Thierry Parmentelat 11 Apr '15

11 Apr '15

Hi there I am using fedora21 for hosts and guests, using lxc containers, and was on vanilla 1.2.9 as exposed by the fedora yum repo The other day I was needing the ability to grant mknod capability to some guests, some chap on IRC kindly pointed me at the <capabilities> tag However I was told that needed 1.2.11 So I went and rebuilt from this download http://libvirt.org/sources/libvirt-1.2.14-1.fc21.src.rpm using plain rmbuild —rebuild Once I had upgraded my host with these new rpms it looked like everything was going fine, and my guests indeed were able to mknod However once I rebooted the host, virsh unpleasantly refused to start any of my containers, and complained like this after hanging for 5 to 10 seconds: 2015-04-11 07:44:10.295+0000: 37843: error : virLXCProcessStart:1263 : internal error: guest failed to start: libvirt: error : Failed to terminate process 37905 with SIGKILL: Device or resource busy — At that point I redid the same with 1.2.13, which gave me the same behaviour, and then 1.2.12 which seems to work for me right now — So it looks like 1.2.13 brings me a regression of some kind I am attaching the XML config for one sample domain, mostly they all look alike Should I file a bug report, and if so where should I do that ? thanks — root@buzzcocks ~ # virsh -c lxc:/// dumpxml testmaster setlocale: No such file or directory <domain type='lxc' id='1528'> <name>testmaster</name> <uuid>18989592-f964-4d51-90af-7ecf7719b758</uuid> <memory unit='KiB'>1048576</memory> <currentMemory unit='KiB'>1048576</currentMemory> <vcpu placement='auto'>1</vcpu> <numatune> <memory mode='strict' placement='auto'/> </numatune> <resource> <partition>/machine</partition> </resource> <os> <type arch='x86_64'>exe</type> <init>/sbin/init</init> </os> <features> <acpi/> </features> <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='/vservers/testmaster'/> <target dir='/'/> </filesystem> <interface type='bridge'> <mac address='52:54:00:ae:8b:47'/> <source bridge='br0'/> <target dev='viftestmaster'/> <guest dev='eth0'/> </interface> <console type='pty' tty='/dev/pts/0'> <source path='/dev/pts/0'/> <target type='lxc' port='0'/> <alias name='console0'/> </console> </devices> </domain>

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[libvirt-users] Detecting that the VM is snapshoting
by Joaquín Rinaudo 11 Apr '15

11 Apr '15

While taking or reverting a snapshot, using virsh --connect qemu:///system dominfo, the state of a VM is paused. Is there a way to distinguish this state (snapshotting) with virsh or any other tools? Joaquín

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