- Users - libvirt List Archives

[libvirt-users] Host should not touch passed-through USB device, how?
by Andreas Ntaflos 01 Jun '10

01 Jun '10

Hello list, this may be off topic but it is closely related to my Libvirt adventures so maybe you can help me. I want to pass a USB device (a USB Huawei E620 modem) through to a KVM guest. Pass-through in general works fine and the modem is visible in the guest. However, the host still sees it and sometimes tries to access it (such modems seem to also be USB storage devices). This naturally leads to conflicts and I believe this crashed the guest very badly yesterday. So I am looking for a way to make sure the host passes through the USB device (in its entirety) without trying to touch it and claim it as its own. Preferably without disabling the USB storage subsystem completely on the host. Any ideas? Is there a best practice for such things in the Libvirt world? Or any other world? Thanks! Andreas -- Andreas Ntaflos GPG Fingerprint: 6234 2E8E 5C81 C6CB E5EC 7E65 397C E2A8 090C A9B4

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[libvirt-users] Qemu driver not supporting VIR_DOMAIN_DEVICE_MODIFY_CONFIG yet?
by Guido Winkelmann 01 Jun '10

01 Jun '10

Hi, According to the docs on http://libvirt.org/html/libvirt-libvirt.html#virDomainDetachDeviceFlags I ought to be able to do virDomainDetachDeviceFlags( <domain>, <devicexml>, VIR_DOMAIN_DEVICE_MODIFY_LIVE | VIR_DOMAIN_DEVICE_MODIFY_CONFIG); to detach a volume both from a currently running VM instance and permanently from the defined config file. If I actually try that, though, I'm getting this error: libvir: QEMU error : Requested operation is not valid: cannot modify the persistent configuration of a domain The same thing happens whether or not the domain is running and also happens if I leave out the "VIR_DOMAIN_DEVICE_MODIFY_LIVE" part. Does the qemu driver simply not support VIR_DOMAIN_DEVICE_MODIFY_CONFIG yet (libvirt 0.8.1), or is there some other problem here? Guido

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[libvirt-users] Monitoring KVM Machine Uptimes
by Karsten Knese 01 Jun '10

01 Jun '10

Hey folks. Currently, I am working on an accounting-solution for Private Cloud with Eucalyptus as my bachelor-thesis. Eucalyptus bases on libvirt providing the KVM machines. Part of the thesis is kind of measurement for the uptimes of each instance in the cloud. As Eucalyptus is based on libvirt, i want to know if there is kind of tool already setup for monitoring a vm in terms of uptimes, cputimes and disk i/o. If not, can anyone give me a hint, how i could grep these facts? I found a tool called "virt-top" which monitors the vm, but for me there is to much overhead. Thanks for you support. cheers, Karsten

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[libvirt-users] FailOver IP
by Christian Hermann 01 Jun '10

01 Jun '10

hi guys! i`am new to libvirt and i want using kvm with a ipv4 failover ip-address. so this addres has the netmask 255.255.255.255. this ip is directly bind to my root server by my provider. so i can not use it on an other server. can you tell me how i can use this ip address on a kvm virtual maschine, build with libvirt? Kind regards, Chris

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[libvirt-users] ballooning option xml
by udo1 01 Jun '10

01 Jun '10

Hi everybody, I need the ballooning option with kvm using libvirt xml file and virsh (virsh create domain.xml) kvm line must be appended with the -balloon virtio switch to enable ballooning. (can be disabled if there no option or with -balloon none ) I currently using Ubuntu Lucid How can I define this in the domain xml file, or what need I to do to get this option? is there any option like enabling with <balloon>virtio</balloon> or disabling with <balloon>none</balloon> Thanks in Advance Udo Attila Fischer

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[libvirt-users] Java Bindings against RHEL5.5 KVM
by James Hogarth 01 Jun '10

01 Jun '10

Hi all, I'm doing some dev work against the native RHEL/centos 5.5 KVM installation for maintenance, creation and deletion of virtual guests using the libvirt API vai the java bindings from a java based web app. Things in general seem to be working - I can connect to and query the kvm instance using the libvirt interface and get a list of guests, pull information about them and stop/start/restart guests. I'm hitting a bit of an issue with creation of a guest however.... When calling domainDefineXML with XML following the domain XML specification (with the XML as per a dumpxml on the relevant box) I get an error creating the guest of: "internal error unknown lifecycle action restart " The virsh version information for the host is: Compiled against library: libvir 0.6.3 Using library: libvir 0.6.3 Using API: QEMU 0.6.3 Running hypervisor: QEMU 0.10.5 I have tried this against my ubuntu system as well with the same error - that has version: Compiled against library: libvir 0.7.5 Using library: libvir 0.7.5 Using API: QEMU 0.7.5 Running hypervisor: QEMU 0.12.3 I'm currently using jna 3.2.5 with libvirt 0.4.5 bindings. The example XML being used is: <domain type="kvm"> <name> newguestfomwebapp </name> <memory> 512 </memory> <vcpu> 1 </vcpu> <os> <type arch="x86_64" machine="rhel5.4.0"> hvm </type> <boot dev="hd"/> </os> <features> <acpi/> <apic/> <pae/> </features> <clock offset="utc"/> <on_poweroff> destroy </on_poweroff> <on_reboot> restart </on_reboot> <on_crash> restart </on_crash> <devices> <emulator> /usr/libexec/qemu-kvm </emulator> <disk type="file" device="cdrom"> <driver name="qemu" type="raw"/> <source file="/var/lib/libvirt/images/ISOs/centos5.5-ks.iso"/> <target dev="hdc" bus="ide"/> <readonly/> </disk> <interface type="network"> <source network="default"/> <model type="virtio"/> </interface> <input type="mouse" bus="ps2"/> <graphics type="vnc" port="-1" autoport="yes"/> </devices> </domain> If I remove the lifecycle information from the xml I get: "unknown OS type hvm " The xml works from the command line with virsh define ... Anyone seen anything similar or have any ideas? Regards, James

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[libvirt-users] Update Libvirt
by Rafael Braga 31 May '10

31 May '10

Hi, I installed the opensuse 11.0 and libvirt version installed is 0.4. But, Nimbus need the version 0.6.3. How do I upgrade? I can't by YAST... thanks! -- Rafael Braga

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[libvirt-users] monitoring kvm machines with libvirt
by Karsten Knese 31 May '10

31 May '10

Hey folks. Currently, i am working on my bachelorthesis. Subject of this thesis is to setup an accounting-solution for the Private Cloud with Eucalyptus. Eucalyptus works with libvirt providing kvm instances. my question is, if i can grep facts like general uptimes, cpu-peaks and disk i/o of each vm with libvirt-tools?! I just found one called virt-top, which monitors each vm, but unfortunately it produces to much overhead. If you should be no tool, can anybody give me a hint, where i best look at to grep these facts? First try is to grep the uptime of each vm by writing a little deamon, checking one time per minute via virsh, if the vm is in state running. But i don't know, if this is best. thanks for your support! cheers, Karsten

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[libvirt-users] VM parameters best practice?
by Guido Winkelmann 31 May '10

31 May '10

Hi, When creating many virtual machines from a template (disk image), you often need to set some different parameters for each vm. Those usually include root passwords and/or ssh public keys for login, ssh Host keys (so that a) not all the VMs have the same host key and b) the user can know the real host key for his vm before connecting for the first time) plus any number of user-defined parameters. IP addresses and hostnames can be set via DHCP. Obviously, some of those parameters need to be treated as confidential, so you cannot just grab them from some FTP server somewhere. In fact, as long as you haven't set any authentication credentials (like an SSL Client Certificate for example) that the vm can use to uniquely and securely identify itself to some server, you cannot securely get any of these parameters over the network. How do people usually solve that sort of problem? What is considered best practice here? Currently, my own plans are to write these parameters to a floppy image, use Unix file permissions to make sure nobody else can read the image, and then hook up that image to a virtual floppy drive in the respective vm. A shell script in the vm template can then read and apply all those parameter at some early stage during the very first boot. Unfortunately, this means mounting the image in the host system, writing the parameters and then unmounting it again - which seems sort of error prone to me in a fully automated environment. (What if two vms are being created simultaneously? What if the script crashes or hangs somewhere between mounting and unmounting the image?) Regards Guido Winkelmann

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[libvirt-users] Cannot create qcow2 images with libvirt 0.8.1
by Guido Winkelmann 31 May '10

31 May '10

Hi, After upgrading to libvirt 0.8.1, I can no longer create empty volumes with no backing store and an explicit format of qcow2. This XML volume definition: <volume> <name>testserverb-data2.img</name> <allocation>0</allocation> <capacity units='G'>20</capacity> <target> <format type='qcow2'/> <permissions> <owner>107</owner> <group>107</group> <mode>0744</mode> </permissions> </target> </volume> yields the error "Cannot run /usr/bin/qemu-img to create /data/testserverb- data.img: Invalid argument" In /var/log/messages on the qemu host I can find the following snippet after that: error : virRunWithHook:933 : internal error '/usr/bin/qemu-img create -f qcow2 /data/testserverb-data.img 0K' exited with non-zero status 1 and signal 0: qemu-img: Image creation needs a size parameter#012 error : virStorageBackendCreateExecCommand:537 : Cannot run /usr/bin/qemu-img to create /data/testserverb-data.img: Invalid argument error : qemudClientReadBuf:1653 : gnutls_record_recv: A TLS packet with unexpected length was received. If I leave out the <format> element and/or specify a <backingStore> element for the volume, it works again. (I suppose the backing store makes it work because in that case qemu-img does not need a size parameter...) The host system is a vanilla Fedora Core 12 system (aside from the upgraded libvirt). Regards, Guido Winkelmann

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