March 2012 - 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 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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[libvirt-users] Thread-safety issues with vbox driver ?
by Jean-Baptiste Rouault 19 Apr '12

19 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] [API reference] confused by CPU time term
by Zhihua Che 16 Apr '12

16 Apr '12

Hi, everyone I'm writing a virtual machine monitor based on libvirt. As I read the api reference, I found I'm confused by some terms. 1, What is cumulative I/O wait CPU time? API reference says that VIR_NODE_CPU_STATS_IOWAIT indicate cumulative I/O wait CPU time. I'm confused by this time. As far as I know, when cpu meets IO wait situation, it will schedule another task, so, how this IO wait time is accounted? 2, How do I get VCPU runtime? In my mind, VIR_DOMAIN_CPU_STATS_CPUTIME indicates the physical cpu time consumed by the domain. Is there any API by which I can query virtual CPU running stats in one domain?

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[libvirt-users] PCI passthrough error
by Jaap Winius 10 Apr '12

10 Apr '12

Hi folks, Has anyone encountered the following PCI passthrough error? error: internal error Process exited while reading console \ log output: char device redirected to /dev/pts/1 assigned_dev_pci_read: pread failed, ret = 0 errno = 2 It's produced after I've detached the PCI device from the base OS and have tried to start up the guest domain. To get to this point, I mostly followed these instructions: http://docs.fedoraproject.org/en-US/Fedora/13/html/Virtualization_Guide/cha… The distro I'm using is Debian squeeze, which by default comes with libvirt 0.8.3 and qemu-kvm 0.12.5, although to avoid a different PCI passthrough error, I used Debian backports for squeeze to upgrade them to libvirt 0.9.8 and qemu-kvm 1.0. The motherboard involved has VT-d support, which I've enabled with the "intel_iommu=on" kernel option (dmesg shows "Intel-IOMMU: enabled"). I did not bother with setsebool because SELinux is disabled. According to lspci, the device I want to pass through to the guest domain, a USB controller, has bus/slot/function 00:1a.0, so I added the following stanza to the <devices> section of my guest domain: <hostdev mode='subsystem' type='pci' managed='yes'> <source> <address domain='0x0000' bus='0x00' slot='0x1a' function='0x0'/> </source> </hostdev> Actually, every time I save this configuration, libvirt changes it to: <hostdev mode='subsystem' type='pci' managed='yes'> <source> <address domain='0x0000' bus='0x00' slot='0x1a' function='0x0'/> </source> <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/> </hostdev> Huh, slot 5? I don't have any PCI devices that use slot 5. Well, at least the system doesn't complain, but I worry that this might be a symptom of something more serious. Anyway, I'd be very grateful if anyone has any tips on how I might avoid the aforementioned error and get PCI passthrough to to work. Thanks, Jaap

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[libvirt-users] Suggestions on building VM disks from scratch
by Dale Amon 03 Apr '12

03 Apr '12

This may not be the best forum to ask, but it does seem to be one where it is as likely as anywhere that someone will have dealt with a similar problem. I need to define a procedure for last resort disaster recovery from an incremental file level backup of the root partition (and any others that are critical.) Now it is easy enough to create a raw virtual disk with dd, then to losetup and do a cfdisk and mkfs, then mount it and rsync the backup onto it. At this point I would like to be able to install grub and make the virtual disk bootable. I have 'issues' with the way grub does things and the way it seems to make certain assumptions for you. The virtual disk is in actuality going to become an hd(0) on the virtual machine; but my past experience with grub is that it is going to assume you really intend to install the MBR on your running system disk; but if you tell it hd(1) then when you try to boot it ain't gonna work. Has anyone dealt with these issues? It's more than just a VM one; I run up against it time and again. A few months ago I attempted to attach a brand new SATA disk via a USB converter to my laptop so I could build a system on it for a machine that has not CD, no floppy, etc, etc. I damn near clobbered my laptop but fortunately caught the problem in time and fixed it before a reboot... in which case I'd have *really* had issues.

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[libvirt-users] virsh - specifying openvz vm sample in domain creation xml
by Jamshaid 31 Mar '12

31 Mar '12

Hello I need to specify the "vm sample name" in domain creation xml. This is the option which is provided to vzctl wtih --config parameter, I can see that in openvz_driver.c there is below code ..... if ((vmdef->profile && *(vmdef->profile))) { ADD_ARG_LIT("--config"); ADD_ARG_LIT(vmdef->profile); } But i am not sure what to put in "domain creation xml" to avail that option ? I cant find anything about it in documentation or around google. Regards James

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[libvirt-users] Libvirt source code cannot built with libnettle.
by Chatsiri Ratana 31 Mar '12

31 Mar '12

Hello All, I try to build dependency library name is gnutls which require by libvirt, but show error us below. $./configure checking for shared library run path origin... done checking whether to use nettle... yes checking for libnettle... no configure: error: *** *** Libnettle 2.4 was not found. I specify macros are LD_LIBRARY_PATH=$LD_LIBRARY_PATH/path_of_nettle_2.4/lib and "PATH:path_of_nettle_2.4/bin/:$PATH" on ~/.bashrc . Why show an errors for requiring libnettle version 2.4? VIM command line for show data in config.log. it's show as below. 739 | #define __EXTENSIONS__ 1 740 | #define _ALL_SOURCE 1 741 | #define _DARWIN_C_SOURCE 1 742 | #define _GNU_SOURCE 1 743 | #define _POSIX_PTHREAD_SEMANTICS 1 744 | #define _TANDEM_SOURCE 1 745 | #define HAVE_FSEEKO 1 746 | #define STDC_HEADERS 1 747 | /* end confdefs.h. */ 748 | #include <nettle/ripemd160.h> 749 | int 750 | main () 751 | { 752 | ripemd160_init (0) 753 | ; 754 | return 0; 755 | } 756 configure:8887: result: no 757 configure:8913: error: 758 *** 759 *** Libnettle 2.4 was not found. Best Regards, Chatsiri Rattana. -- :-------------------------------------------------------- http://about.me/chatsiri.ratana

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[libvirt-users] vzctl 3.1 not supported in virsh ?
by Jamshaid 31 Mar '12

31 Mar '12

Hello If i use virsh with vzctl 3.1 i get below error virsh -c openvz:///system error: /Could not extract vzctl version It works ok with vzctl 3.0.x Is there any way i can use virsh with vzctl 3.1 ? ---------------------------------------------------------------- [root@test ~]# /usr/bin/virsh --version=long Virsh command line tool of libvirt 0.9.11 See web site at http://libvirt.org/ Compiled with support for: Hypervisors: QEmu/KVM UML OpenVZ VirtualBox Test Networking: Remote Daemon Network Bridging Nwfilter Storage: Dir Filesystem SCSI Multipath iSCSI LVM Miscellaneous: Secrets Debug -------------------------------------------------------- [root@test ~]# vzctl --version vzctl version 3.1 -------------------------------------------------------- Regards James /

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[libvirt-users] virsh create failed: cannot set CPU affinity on process 0
by 杨镭 30 Mar '12

30 Mar '12

Hello Everyone: We can't create vm on a physical server with 64 CPU(as reported by /proc/cpuinfo). The error message is: "cannot set CPU affinity on process 0" The following is the capabilities detected by libvirt: <arch>x86_64</arch> <model>Westmere</model> <vendor>Intel</vendor> <topology sockets='4' cores='10' threads='2'/> I wonder if libvirt uses incorrect CPU topology information to set process affinity which lead to the error above.

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