- Users - libvirt List Archives

[libvirt-users] fstrim support in libvirt/qemu guests
by Dennis Jacobfeuerborn 04 Nov '14

04 Nov '14

Hi, I'm trying to find out how to enable fstrim support for libvirt/qemu guests. Specifically I'm trying to enable this on a CentOS 7 host (qemu 1.5). I searched the web but only found very vague information and no clear documentation on the requirements or how to modify the guest xml to enable discard/fstrim support. Can someone point me in the right direction? Regards, Dennis

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[libvirt-users] The USB passthrough that refuses to die
by Mauricio Tavares 04 Nov '14

04 Nov '14

In trying to find out why my usb passthrough is not working, I decided to edit (virsh edit) the config file for the vm client, removing the following lines <hostdev mode='subsystem' type='usb' managed='yes'> <source> <vendor id='0x051d'/> <product id='0x0002'/> </source> </hostdev> checking with "virsh dumpxml" that the lines went away, and then restarting [root@vmhost ~]# virsh start nagios error: Failed to start domain nagios error: internal error Did not find USB device 51d:2 bus:2 device:3 [root@vmhost ~]# As you can see, it is still acting like the usb device is defined. What am I missing here?

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[libvirt-users] KVM incremental backup using CBT
by Jd 03 Nov '14

03 Nov '14

Hi Looking in to implementing (CBT like) delta backup for KVM. The following looks promising..(last paragraph) http://wiki.qemu.org/Features/Snapshots2 * In the last para, there is a mention of copy the blocks from the disk using dirty-bitmap as reference. How to accomplish this ? block-mirror with bitmap or is there a qemu-img command ? some details would be appreciated. // backup software now reads foo.img using t0_dirty.dbmp to perform incremental backup, when finished * The backup after few runs in the backup store would be base image + bunch of delta blocks ? Will this be same as base disk and bunch of deltas ? or there is some special way to merge these ? * I am assuming this scheme (snapshot, bitmap, block merge etc.) should work with base disk in raw (non-qcow) format as well ? Right ? i.e. will it work when the storage disk is iscsi, lvm, fc ? std linux block device? * Are there libvirt-api/verbs for doing some of this or we will have to sue the qemu-monitor-command ? * What version of qemu/kvm will have the core capabilities and which min libvirt version would be sufficient ? Is there a better way to do incremental backup / CBT like backup than one mentioned here ? Thanks /Jd

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[libvirt-users] quick question on schedinfo
by Yasser Shalabi 01 Nov '14

01 Nov '14

Hey everyone, Can anyone explain the scedinfo parameters? I am wondering if I can use this, (along with host side niceness scheduler tweaks) to cause vCPUs to dominate the total time of the CPUs they are pinned to. Here are the sched info parameters: Scheduler : posix cpu_shares : 0 vcpu_period : 0 vcpu_quota : 0 emulator_period: 0 emulator_quota : 0 The documentation ( http://libvirt.org/sources/virshcmdref/html/sect-schedinfo.html) is not yet filled for this. If anyone can explain these parameters, or point me to relevant code it would be helpful! Thanks Yasser

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[libvirt-users] reboot problem with libxl
by Alvin Starr 01 Nov '14

01 Nov '14

If I reboot a single vm through libvirt/libxl the system reboots normally. If I have several vm's reboot at the same time then The systems go into a paused state and do not reboot. I then have to kill them via xl and restart them. -- Alvin Starr || voice: (905)513-7688 Netvel Inc. || Cell: (416)806-0133 alvin(a)netvel.net ||

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[libvirt-users] VNC display size
by Aaron Bruelisauer 31 Oct '14

31 Oct '14

Hi I would like to set the resolution of the video device of my domain. So if I connect with via vnc I see more. That is the part of the .xml file: "... <graphics type='vnc' port='-1' autoport='yes'/> <video> <model type='cirrus' vram='9216' heads='1'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/> </video> ..." How can I change it? Salutations Aaron

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[libvirt-users] problem with libvirt and ovs
by Anna Giannakou 31 Oct '14

31 Oct '14

Hello, I have defined an ovs network with libvirt (virsh net-define ovs.xml) and created a vm that will connect to that network with virt-install. Although the vm port appears normally if i do an ovs-vsctl show, when i try to set this port as a mirror port for all the traffic in the bridge, the command is executed normaly, but then i cannot see any traffic on the interface. Could you give me some hints for that? The ovs.xml: <network> <name>ovs-network</name> <forward mode='bridge'/> <bridge name='br-tun'/> <virtualport type='openvswitch'/> </network> the virt-install command: virt-install --connect qemu:///system --name snort3 --ram 2048 --disk path=/tmp/snort.qcow2,device=disk,format=qcow2 --graphics vnc --vcpus 2 --hvm --network network=ovs-network --import the ovs command for mirroring ovs-vsctl -- set interface vnet0 type=internal -- --id=@p get port vnet0 -- --id=@m create mirror name=m0 select-all=true output-port=@p -- set bridge br-tun mirrors=@m if i execute the same command with another interface then i see the traffic normally. Thank you Anna

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[libvirt-users] Revert to internal snapshot - XML error: Non-empty feature list specified without CPU model
by Kashyap Chamarthy 31 Oct '14

31 Oct '14

Versions: $ rpm -q libvirt-daemon-kvm qemu-system-x86 libvirt-daemon-kvm-1.2.9-3.fc21.x86_64 qemu-system-x86-2.1.2-4.fc21.x86_64 When I attempt to revert to an internal snapshot: $ virsh snapshot-list node1 Name Creation Time State ------------------------------------------------------------ snap1 2014-06-03 14:07:28 -0400 running $ virsh snapshot-revert node1 snap1 error: XML error: Non-empty feature list specified without CPU model Contextual guest XML: $ virsh dumpxml node1 | grep features -A3 <features> <acpi/> <apic/> <pae/> </features> <cpu mode='host-passthrough'> </cpu> <clock offset='utc'> I see it's thrown from here, src/conf/cpu_conf.c, from function: virCPUDefParseXML:371 [. . .] 367 if (n > 0) { 368 if (!def->model && def->mode != VIR_CPU_MODE_HOST_MODEL) { 369 virReportError(VIR_ERR_XML_ERROR, "%s", 370 _("Non-empty feature list specified without " 371 "CPU model")); 372 goto error; 373 } [. . .] I can manually revert this snapshot via `qemu-img`, but wondering if this error from libvirt expected in this case? -- /kashyap

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[libvirt-users] libvirt with VirtualBox - possible to specify path to snapshot folder in domain.xml?
by fdytr ytruy 30 Oct '14

30 Oct '14

Hi! I'm using libvirt withVirtual Box. I have installed libvirt 0.10.2 and Virtual Box 4.1.Is possible to spesify the pat to the folder I want my differencing image created in in my domain.xml file? When I define my vm (virsh domain.xml) with my domain.xml and use the readonly tag, Virual Box creates a differencing image (default in users Vitual Box VMs folder). I want to specify in my domain.xml file what folder this differencing image should be created in (not the default folder). Is this possible? LL

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[libvirt-users] Can't specify filename.xml when using virsh dumpxml
by Allen Qiu 30 Oct '14

30 Oct '14

Hi all, Do you have any idea about this error? virsh # dumpxml csg01win7test > domain.xml error: unexpected data '>' Regards, Allen 2014-10-28 Allen Qiu

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