September 2011 - Users - libvirt List Archives

[libvirt-users] converting save/dump output into physical memory image
by Andrew Tappert 04 Jun '12

04 Jun '12

A lot of people in the security community, myself included, are interested in memory forensics these days. Virtualization is a natural fit with memory forensics because it allows one to get access to a guest's memory without having to introduce any extra software into the guest or otherwise interfere with it. Incident responders are particularly interested in getting memory dumps from systems they're investigating. Virsh has "save" and "dump" commands for storing the state of a guest to a file on disk, but memory of KVM guests doesn't get saved in the "standard" input format for memory forensics tools, which is a raw physical memory image. (This is what you'd get via the classical "dd /dev/mem" approach or the contemporary equivalent using the crash driver; and VMware Server and Workstation produce .vmem files, which are such raw physical memory images, when a guest is paused or snapshotted.) In order to analyze the memory of Libvirt/KVM guests with my Linux memory forensics software, Second Look, I've created a tool for converting Libvirt-QEMU-save files (output of virsh save command) or QEMU-savevm files (output of virsh dump command) to raw physical memory images. I've got a basic working capability, though I'm still tracking down some problems with a guest allocated 8GB RAM--not all the memory seems to be present in the save or dump file. And I haven't tested very extensively yet, version support is limited to what I myself am currently running, etc. I'd like to know if this is a capability that others are interested in. Is this something that would be of interest to the Libvirt project if I were to contribute the code, or to the KVM project, or do you think it best exists as a separate project? I've also got a proof-of-concept tool for converting hibernate images to raw physical memory images. Perhaps a collection of tools for converting various memory dump formats would be a good project. Anyone else interested in this kind of stuff? As an author of commercial memory forensics software I've got a vested interest in availability of good memory acquisition capabilities. But there are a number of people working on FOSS Linux memory analysis tools, too... Andrew

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Re: [libvirt-users] ruby-libvirt 0.4.0
by Chris Lalancette 09 Nov '11

09 Nov '11

On 07/29/11 - 09:34:17AM, David M. Barlieb wrote: > Hi, I'm fairly new to using libvirt. I have RHEL6 servers running KVM > virtual environment. As I understand it, libvirt provides the tools to > the KVM environment so that I can create domains or virtual guests. So, > that being said, what does this ruby-libvirt provide me or enhance given > my current setup. > > > > I'll understabnd if this is a little rudimentary but I really do not > know who or where else to ask these types of question. I get quite a bit > of email from the libvirt-users groups about libvirt and really have no > idea if I can or should put any of these into my current setup, or if I > should be asking RedHat this. > > > > I certainly wouldn't mind testing and contributing to these effort to > enhance the libvirt tools and KVM hypervisor but think I need a better > understanding of exactly how libvirt and KVM interact and what the > enhancements bring to the table. In the future it is usually best to keep one of the lists on an email; that way, if I'm away or not responding, someone else can help you. I've added libvirt-users to this response. In any case, you have the right idea. Libvirt is a control plane for various different virtualization solutions. Arguably the most popular virtualization solution that libvirt can control is KVM, but it can also manage Xen, VMware ESX, LXC (linux containers), UML, etc. Libvirt provides both tools (like virsh and libvirtd) and APIs for interacting with virtual machines. The APIs are things like virDomainShutdown(), virDomainReboot(), etc. The ruby-libvirt package is a thin wrapper around these APIs, so that you can use this functionality from ruby programs. That is, you would be able to do something like: dom.reboot dom.shutdown from your ruby programs. There are also bindings for other languages such as python, php, and perl. There is a lot more information at http://libvirt.org, and there is more information specifically about the ruby bindings at http://libvirt.org/ruby -- Chris Lalancette

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[libvirt-users] Second VM cannot get dhcp ip in NAT mode
by Magicloud Magiclouds 03 Oct '11

03 Oct '11

Hi, Yesterday I started to use libvirt with kvm under centos6. The first VM works great. Today I added another VM and start to initialize with virt-install. Well, it seems that, the second VM cannot get dhcp ip. I did not change the default libvirt network configuration. What should I do? -- 竹密岂妨流水过山高哪阻野云飞

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[libvirt-users] Difficutlies with lp port
by Anselmo 30 Sep '11

30 Sep '11

Hello, I'm using libvirt on debian as host and Windows XP Home as guest. I would like to pass the /dev/parport0 to XP to attach a printer. I use virt-manager. When I add a parallel port as a "dev" type I got this conf file: .... <parallel type='dev'> <source path='/dev/parport0'/> <target port='0'/> </parallel> .... And this command line: .... -chardev tty,id=charparallel0,path=/dev/parport0 -device isa-parallel,chardev=charparallel0,id=parallel0 .... The first parameter is "tty".Should not it be "parport"? Anyway I never see any parallel port on the guest with these options. Even starting kvm from the command line. While is seems to work immediatly using the kvm option: "-parallel /dev/parport0" Where i've made a mistake? Or how can I just tell libvirt to use the "-parallel" option instead. Thank's for your help Anselmo Luginbühl

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[libvirt-users] win7 instance just disappears
by Alex 30 Sep '11

30 Sep '11

Hi, I have a fedora15 box with a win7 kvm instance that has been running for some time, but lately it seems to just crash and disappear without any idea of what happened. It's never happened while I have been using it, only when the instance is idle. I usually start the instance using virt-manager, but also start it just using "virsh start mykvm" then access it using the spicec client. I can't find any logging information to indicate why this is happening or how to go about fixing it. I've tried accessing it using the normal virt-manager client as well as the spicec client an it doesn't make any difference. When it crashes, the whole process is gone. Is there something that could cause it to do this when the system is idle? I also installed the qxl video drivers (qxl-win-0.1010-20110308-d9eb3203bd) some time ago, so it could possibly be related to that. I thought it might be helpful to have a copy of the qemu XML file: <domain type='kvm'> <name>alex-win7</name> <uuid>f7decb31-88cf-d003-8716-66258550b996</uuid> <memory>3145728</memory> <currentMemory>3145728</currentMemory> <vcpu>1</vcpu> <os> <type arch='x86_64' machine='pc-0.14'>hvm</type> <boot dev='hd'/> </os> <features> <acpi/> <apic/> <pae/> </features> <cpu match='exact'> <model>Opteron_G3</model> <vendor>AMD</vendor> <feature policy='require' name='skinit'/> <feature policy='require' name='vme'/> <feature policy='require' name='mmxext'/> <feature policy='require' name='fxsr_opt'/> <feature policy='require' name='cr8legacy'/> <feature policy='require' name='ht'/> <feature policy='require' name='3dnowprefetch'/> <feature policy='require' name='3dnowext'/> <feature policy='require' name='wdt'/> <feature policy='require' name='extapic'/> <feature policy='require' name='pdpe1gb'/> <feature policy='require' name='osvw'/> <feature policy='require' name='cmp_legacy'/> <feature policy='require' name='3dnow'/> </cpu> <clock offset='localtime'/> <on_poweroff>destroy</on_poweroff> <on_reboot>restart</on_reboot> <on_crash>restart</on_crash> <devices> <emulator>/usr/bin/qemu-kvm</emulator> <disk type='file' device='disk'> <driver name='qemu' type='raw'/> <source file='/home/libvirt-images/alex-win7.img'/> <target dev='hda' bus='ide'/> <address type='drive' controller='0' bus='0' unit='0'/> </disk> <disk type='file' device='disk'> <driver name='qemu' type='raw'/> <source file='/home/libvirt-images/alex-win7a-2.img'/> <target dev='vda' bus='virtio'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/> </disk> <controller type='ide' index='0'> <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/> </controller> <controller type='virtio-serial' index='0'> <address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x0'/> </controller> <interface type='bridge'> <mac address='52:54:00:6c:6c:47'/> <source bridge='br0'/> <model type='virtio'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/> </interface> <serial type='pty'> <target port='0'/> </serial> <console type='pty'> <target type='serial' port='0'/> </console> <channel type='spicevmc'> <target type='virtio' name='com.redhat.spice.0'/> <address type='virtio-serial' controller='0' bus='0' port='1'/> </channel> <input type='mouse' bus='ps2'/> <graphics type='spice' autoport='yes'/> <sound model='ich6'> <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/> </sound> <video> <model type='qxl' vram='9216' heads='1'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/> </video> <memballoon model='virtio'> <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/> </memballoon> </devices> </domain> Thanks, Alex

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[libvirt-users] ANNOUNCE: Perl binding release Sys-Virt version 0.9.5
by Daniel P. Berrange 29 Sep '11

29 Sep '11

I am pleased to announce a new release of the Perl binding, Sys::Virt version 0.9.5, is now available for download: http://search.cpan.org/CPAN/authors/id/D/DA/DANBERR/Sys-Virt-0.9.5.tar.gz Changes in this release - Add all new APIs in libvirt 0.9.5 - Add missing snapshot creation/lookup methods - Fix typo in method listing snapshots - Add missing snapshot constant - Add example for save/restore usage - Re-add abort job binding accidentally deleted All historical releases and online documentation are available from the CPAN page http://search.cpan.org/dist/Sys-Virt/ There is no planned update for libvirt 0.9.6, since that did not introduce any new APIs that require work in the Perl layer. Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|

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[libvirt-users] virsh cannot list broken guest.
by Magicloud Magiclouds 29 Sep '11

29 Sep '11

Hi, I am starting to learn using libvirt with kvm on CentOS 6. Just used this command to start a guest: virt-install -ntest -r1024 --vcpus=1 -c/var/lib/libvirt/images/CentOS-6.0-x86_64-netinstall.iso --os-type=linux --os-variant=rhel6 --disk vol=kvmguests/test --vnc -v --virt-type=kvm --check-cpu --prompt --arch=x86_64 Then I found out that I misconfigured vnc. And I do not know how to gracefully stop qemu. So I killed it. Then with the command, I got: ERROR Guest name 'test' is already in use. What is the name of your virtual machine? But at this time, there is nothing listed in virsh: Welcome to virsh, the virtualization interactive terminal. Type: 'help' for help with commands 'quit' to quit virsh # list Id Name State ---------------------------------- virsh # connect qemu:///system virsh # list Id Name State ---------------------------------- virsh # What should I do? -- 竹密岂妨流水过山高哪阻野云飞

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[libvirt-users] Snapshot Error
by huachao yao 28 Sep '11

28 Sep '11

Hey When I want to take a snapshot for a Domain by using virDomainSnapshotCreateXML. The Error as below happen: libvir: QEMU error : Requested operation is not valid: Disk '/var/lib/libvirt/images/fedora-qcow.qcow2' does not support snapshotting The snapshot Configuration is : <domainsnapshot> <description>Snapshot of OS install and updates</description> <disks> <disk name='/var/lib'> <source file='/var/lib-snapshot'/> </disk> <disk name='vdb' snapshot='no'/> </disks> </domainsnapshot> And /var/lib/libvirt/images/fedora-qcow.qcow2 is the disk for the domain (use qemu-img to create). And I had tried another Disk format (*.img), but the error still happen. how can i deal with this error?? PS:qemu version is 0.14 & libvirt version is 0.9.4. Pls help. :-(

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[libvirt-users] how to convert from xen .cfg files to libvirt xml?
by Mauro 27 Sep '11

27 Sep '11

I have a .cfg configuration file for a xen virtual machine. I need to convert it in xml format to use with libvirt. So I run virsh domxml-from-native xen-xm backupsrv.cfg but I have an error: error: Unknown failure. How can I investigate about the error?

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[libvirt-users] virsh edit problems
by Robin Lee Powell 26 Sep '11

26 Sep '11

I've got a problem where I can't access my console (well, I can', but I can't type in a password), which I don't think is a libvirt issue but any help or commentary is certainly welcome http://thread.gmane.org/gmane.comp.emulators.kvm.devel/79561 , and I'm trying to debug it by trying out different console/serial options in my .xml file, and I can't change them. What I have now: <serial type='pty'> <target port='0'/> </serial> <console type='pty'> <target type='serial' port='0'/> </console> No matter what I change, whether I use "virsh edit" or edit the files directly, even with libvirt off, as soon as libvirt notices (i.e. when I turn it back on) my changes get blown away and it ends up looking just like the above. Even as simple a thing as changing the port number, or removing the console, or adding a second serial... all gone. Oh, wait, that's not quite true; adding a second serial *does* work. But nothing else I've tried does. What I'm actually trying to do is copy the docs http://libvirt.org/formatdomain.html#elementsConsole more closely and specify my own source paths; I'm worried that the serial and the console are somehow ending up in the same place and maybe that's causing my problem? What I've been trying to do is something like: <serial type='pty'> <source path='/dev/pts/3'/> <target port='0'/> </serial> <console type='pty'> <source path='/dev/pts/4'/> <target port='0'/> </console> And it just won't stick. Maybe that's not even my problem, but it's not showing any errors, and it's annoying me and I'd like to understand why. -Robin

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