December 2011 - Users - libvirt List Archives

[libvirt-users] virsh list not working with xen 4
by Rogério Vinhal Nunes 21 Sep '12

21 Sep '12

Hi, I'm having some trouble to get libvirt to show the correct power state of my virtual machines. I'm using Ubuntu 10.04 + Xen 4.1.1 + libvirt 0.8.8. virsh list --all only shows turned off machines registered in xend. If I turn them on, they just "disappear", and when I start machines directly from xml, they just doesn't appear at all. Libvirt is correctly connecting to xen as I can use the other commands fine, just the list option doesn't seem to work at all. What can I do to change that? # virsh version Compiled against library: libvir 0.8.8 Using library: libvir 0.8.8 Using API: Xen 3.0.1 Running hypervisor: Xen 4.1.0

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[libvirt-users] converting save/dump output into physical memory image
by Andrew Tappert 05 Jun '12

05 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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[libvirt-users] Thread-safety issues with vbox driver ?
by Jean-Baptiste Rouault 20 Apr '12

20 Apr '12

Hi, I'm experiencing weird things with the vbox driver when using multiple threads. Following is the snippet of code I experience problems with /*****************************************************/ #include <stdlib.h> #include <stdio.h> #include <pthread.h> #include <libvirt/libvirt.h> void *create_and_destroy(void *arg) { virDomainPtr dom = (virDomainPtr)arg; char buf[VIR_UUID_STRING_BUFLEN]; virDomainGetUUIDString(dom, buf); if (virDomainCreate(dom) != 0) { printf("failed to start %s\n", buf); goto end; } printf("%s started\n", buf); if (virDomainDestroy(dom) != 0) { printf("failed to destroy %s\n", buf); } printf("%s destroyed\n", buf); end: virDomainFree(dom); pthread_exit(NULL); } int main(int argc, char **argv) { virConnectPtr conn = virConnectOpen("vbox:///session"); int i; int count = virConnectNumOfDefinedDomains(conn); char **names = malloc(count * sizeof(char *)); virConnectListDefinedDomains(conn, names, count); virDomainPtr *doms = malloc(count * sizeof(virDomainPtr)); for (i = 0 ; i < count ; ++i) { doms[i] = virDomainLookupByName(conn, names[i]); } pthread_t *threads = malloc(count * sizeof(pthread_t)); pthread_attr_t attr; pthread_attr_init(&attr); pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE); for (i = 0 ; i < count ; ++i) { pthread_create(&threads[i], &attr, create_and_destroy, (void *)doms[i]); } pthread_attr_destroy(&attr); for (i = 0 ; i < count ; ++i) { pthread_join(threads[i], NULL); } virConnectClose(conn); pthread_exit(NULL); } /************************************************/ Here is the output of the program with 2 defined domains: > libvir: VBOX error : operation failed: OpenRemoteSession/LaunchVMProcess failed, domain can't be started > failed to start c538c89a-70da-42ab-a88a-5aeb15698c12 > 034cf837-abe7-4c48-8373-0ddcf480d416 started > 034cf837-abe7-4c48-8373-0ddcf480d416 destroyed Sometimes the first domain really fails to start, but sometimes it starts correctly but libvirt reports an error. Sometimes domains aren't destroyed but libvirt reports no error at all. If there is only one domain, no problem occurs at all. I also tried the same code (ie with multiple domains) but with only one thread and it works well. I managed to reproduce these issues with libvirt 0.9.4, 0.9.7, using VirtualBox 4.0 and 4.1. -- Jean-Baptiste ROUAULT Ingénieur R&D - diateam : Architectes de l'information Phone : +33 (0)9 53 16 02 70 Fax : +33 (0)2 98 050 051

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[libvirt-users] Network questions
by paul.worner＠thomsonreuters.com 06 Feb '12

06 Feb '12

Hi all, When creating a new network: 1) Is there a way to disable automatic spawning of dnsmasq on network creation? I read that leaving out the <DHCP> section should accomplish this, but that is not what I am seeing. 2) Is there a way to disable automatic installation of iptables rules? 3) For that matter, what is the purpose of the default iptables rule set? Doesn't line 3 let all traffic pass anyway? Thanks, Paul Running libvirt 0.9.2 on Ubuntu 11.10 server. Here's the libvirt network config: RAW CONFIG <network> <name>test</name> <bridge name="virbr%d" stp="off" delay="0"/> <forward mode="route"/> <ip address="192.168.0.1" netmask="255.255.255.0"> </ip> </network> COMMAND virsh net-create test.xml RESULTS virsh net-dumpxml test <network> <name>test</name> <uuid>2eff5e7f-847a-1fbf-ec82-01a46ef0f6c2</uuid> <forward mode='route'/> <bridge name='virbr3' stp='off' delay='0' /> <mac address='52:54:00:47:E6:15'/> <ip address='192.168.0.1' netmask='255.255.255.0'> </ip> </network ps aux | grep dns nobody 4391 0.0 0.0 21616 916 ? S 09:45 0:00 dnsmasq --strict-order --bind-interfaces --pid-file=/var/run/libvirt/network/test.pid --conf-file= --except-interface lo --listen-address 192.168.0.1 iptables -L --line-numbers Chain FORWARD (policy ACCEPT) num target prot opt source destination 1 ACCEPT all -- anywhere 192.168.0.0/24 2 ACCEPT all -- 192.168.0.0/24 anywhere 3 ACCEPT all -- anywhere anywhere 4 REJECT all -- anywhere anywhere reject-with icmp-port-unreachable 5 REJECT all -- anywhere anywhere reject-with icmp-port-unreachable

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[libvirt-users] Libvirtd slowness
by Nathan March 07 Jan '12

07 Jan '12

Hi, Can anyone tell me if it's normal to take over 2 seconds to connect to the libvirt daemon? xen1 ~ # time virsh -c 'xen://xen5/' pwd real 0m2.102s xen1 ~ # time virsh -c 'xen://xen1/' pwd real 0m2.217s Strace shows it sitting for 2.08s on polling the remote socket: poll([{fd=6, events=POLLIN}, {fd=7, events=POLLIN}], 2, -1) = 1 ([{fd=6, revents=POLLIN}]) <2.082839> Not quite sure why though? Experiencing this on both 0.9.7 and 0.9.0. This happens both with virsh and the perl libvirt bindings. If i just spawn virsh interactively I only incur that 2s hit on intial spawn, all commands are very quick and responsive. Anyone have any suggestions? - Nathan -- Nathan March<nathan(a)gt.net> Gossamer Threads Inc. http://www.gossamer-threads.com/ Tel: (604) 687-5804 Fax: (604) 687-5806

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[libvirt-users] How to connect to a remote VM ESXi server with Python language?
by ice 30 Dec '11

30 Dec '11

Hi, Dear Mr/Mrs. I have trouble in connecting to a VM ESXi server with python. I am a developer using libvirt to control remote VM ESXi with python language. But I am not able to connect to a remote VM ESXi server. I make my try to solve this issue: 1: I use the function libvirt.Open() to open the remote VM ESXi Server, but I don't know how to input the password. It seems that there is no parameter for password input. 2: I use "virsh connect ---". It is succeed when it is executed on locale machine manual, but failed when I invoke this command in python environment. I use "subprocess.Popen" to execute the command "virsh", but this function would be hung on after command "communicate" executed. -bash-4.1# python Python 2.6.6 (r266:84292, May 20 2011, 16:42:11) [GCC 4.4.5 20110214 (Red Hat 4.4.5-6)] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> from subprocess import Popen,PIPE,STDOUT >>> command=['virsh', '-c', 'esx://192.168.58.144/?no_verify=1','list', '--all'] >>> p=Popen(command, stdin=PIPE,stdout=PIPE, stderr=STDOUT) >>> output = p.communicate()[0] How to fix it? Thanks for help! Best regards!

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[libvirt-users] redirect ports from user network
by Алексей Беляев 30 Dec '11

30 Dec '11

Hello. I would like to redirect some ports from user network to host system. In console i can do it: /usr/libexec/qemu-kvm -drive file=/home/libvirt/qemu-fedora.img -vnc 10.200.1.1:1 -net user -redir tcp:22000::49999 -redir tcp:22001::22 How can i do it with libvirt? I make users network in XML config VM: <interface type='user'> <mac address='52:54:00:48:3f:f5'/> <alias name='net0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/> </interface> But i don't know - how to make redirecting ports and i cann't fint it in documentation. Is it possible? -- Thanks for your feedback. Best regards, Alex

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[libvirt-users] cannot find -lportablexdr
by Juliano Souza 28 Dec '11

28 Dec '11

When I try to compile libvirt: checking for xdrmem_create in -lportablexdr... no checking for library containing xdrmem_create... no configure: error: Cannot find a XDR library Where have that libxdr source? Thanks. -- Juliano Souza

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[libvirt-users] Libvirt java from Windows
by Sergey Sudakovich (ssudakov) 24 Dec '11

24 Dec '11

I am writing a java based client that would be executed from windows that will use libvirt. 1. Got libvirt-java ( http://libvirt.org/sources/java/libvirt-java-0.4.7.tar.gz) and build a jar out it (ant with no params) 2. Then, according to http://libvirt.org/windows.html, built a dll using the "MSYS build script" 3. Got 2 files libvirt-0.dll and libqemu-0.dll When I run the sample example(from Eclipse) from http://libvirt.org/java.html I get the following error: Exception in thread "main" java.lang.UnsatisfiedLinkError: Unable to load library 'virt': %1 is not a valid Win32 application. at com.sun.jna.NativeLibrary.loadLibrary(NativeLibrary.java:169) at com.sun.jna.NativeLibrary.getInstance(NativeLibrary.java:242) at com.sun.jna.Library$Handler.<init>(Library.java:140) at com.sun.jna.Native.loadLibrary(Native.java:368) at com.sun.jna.Native.loadLibrary(Native.java:353) at org.libvirt.jna.Libvirt.<clinit>(Unknown Source) at org.libvirt.Connect.<clinit>(Unknown Source) at Main.main(Main.java:26) Also tried instead of step 2 cross compile in Fedora - same error message when I use new dll's. Does anybody have any idea where do I start fixing the issue?? -- Thank you, Sergey Sudakovich

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[libvirt-users] for a guest accessing host "full disk", how to prevent host vgscan
by David Mansfield 24 Dec '11

24 Dec '11

Hi All. I have a dell system with a H700 raid. Within the hardware RAID config I've created a "virtual disk" which I have assigned to one of my guests. On the host the device is "/dev/sdb", on the guest it's "/dev/vdb". This works fine. Within the guest, we have created lvm PV on /dev/vdb (using the whole disk - no partitions) and created a volume group. The guest's hostname is "argo" and the vg is called "vg_argo_bkup". When I reboot the host, it does a vgscan and finds the volume group and activates it in the _host_, which I need to prevent (I think??). I have successfully done this by filtering "/dev/sdb" in /etc/lvm/lvm.conf (which does NOT work as advertised BTW), but referencing the extremely volatile SCSI "sd*" names seems a terrible way to do this. If I fiddle around in the HW raid config, the /dev/sd? may change. I plan on creating about 10 more VM's spread over a number of machines over the next weeks with a very similar setup, and the admin overhead seems like it'll be onerous and error-prone. I'd love to be able to filter the volume groups by VG name instead of pv device node. The host's hostname is "narnia" and I'd love to say, 'vgscan --include-regex "vg_narnia.*"' or something similar, if you get my drift. Does anyone have a best practice for this? I'm sure iSCSI enthusiasts must have the exact same issue all the time. Oh... I'm using centos 6.2 on host and guest, libvirt-0.9.4-23.el6_2.1.x86_64, although it hardly seems a libvirt issue at all, it seems to be a lvm host issue mainly. Thanks, David Mansfield

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