QEMU stands for "Quick EMUlator" and is a processor emulator that relies on dynamic binary translation to achieve a reasonable speed while being easy to port to new host CPU architectures.

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port forwarding with libvirt

I'm trying to get port forwarding working through libvirt on top of QEMU and KVM. I found this article (https://snippets.webaware.com.au/howto/running-qemu-with-port-redirection-through-libvirt/), but ...
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How do I connect to my libvirt/qemu/guests ? (with no ip address)

I have inherited the administration of a trusty ubuntu server with several virtual servers, also ubuntu using libvirt and qemu. I have the problem I cannot connect to these virtual servers/guests. ...
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4answers
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libvirt and qemu/kvm -snapshot option

Using libvirt, I want to use QEMU's '-snapshot' option. That way, when the machine shuts down, all of the disk changes that were made get destroyed. Here is the manual for the -snapshot option: ...
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1answer
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Vagrant (Virtualbox) host-only multiple node networking issue

I'm trying to use a multi-VM vagrant environment as a testbed for deploying OpenStack, and I've run into a networking problem with trying to communicate from one VM, to a VM-inside-of-a-VM. I have ...
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8k views

Monitor VM's resources (CPU, RAM etc)

I'm testing Openstack and i'd like to know how can i find out about resource utilization inside instances (Virtual Machines). Openstack uses kvm, qemu and libvirt in my testing environment. Is there ...
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1answer
1k views

How to fix a frozen qemu VM?

I have a qemu hypervisor on RHEL 6.4 that hosts VMs that will quite often lose their connection to the network. When the VM has lost its connection I can view and interact with the it using ...
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2answers
1k views

setting CPU cache size and model for KVM guest

Is there any possibility to create a custom CPU model for KVM Linux guests, or at least to modify parameters such as cache size and model name? I know I can set CPU features, topology and pinning and ...
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1answer
44 views

Best options for KVM/qemu/libvirt VM migrations without shared storage

My team has recently been tasked with improving the virtualization infrastructure at the company and one thing we're looking into doing is speeding up migrations. We use local storage only on all VM ...
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1answer
53 views

Backup of running KVM qcow2 VPS

I want a robust method of taking backup of KVM VPS of qcow2 file, while running. After searching for a long time I found that we can use rsync for live backup. I used following command for rsync: ...
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1answer
1k views

Debian Jessie Qemu KVM GPU Passthrough to Windows Virtual Machine guest Virt-Manager error Bus PCI not found

I'm having problems with Virt-Manager not wanting to boot a VM and giving error: Error starting domain: internal error: process exited while connecting to monitor: char device redirected to ...
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Find Qemu-KVM Version on Centos

Apologies if this has already been asked, I have been searching for the last 30 minutes or so and I still can't find it. I was wondering is there a way for me to find what version of qemu-kvm that I ...
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35 views

Running a virtual machine remotely; connect it to the local network

The scenario is as follows: I have a virtual machine remotely, e.g. on a server somewhere in a data center, and I connect to it from my laptop on a restricted network (only tcp 80 and 443 are open). ...
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Guest networking not working on Debian Jessie Host server KVM with br0 bridged network

GUESTS networking not working at all. In other words guest can not ping host or lan gateway. I have br0 bridge already created, also brctl show that vnet0 was properly added by KVM to br0 on guest ...
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3answers
3k views

How can I change Qemu KVM machine architecture from 440fx to q35 with virsh edit or virt-manager

Still trying to get GPU passthrough working and decided to change machine type from older 440fx to q35 ie pc-q35 but if I do virsh edit on the config it refuse to save saying "PCI Bridges not ...
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1answer
33 views

Installed KVM, but Virtual Machine Manager says localhost(QEMU)

My understanding is that KVM uses the CPU virtualization properties and is much faster than QEMU, which is emulation. I used the Virtual Machine Manager to create the virtual machine. I am nearly ...
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2answers
20k views

'Unrecognised disc label' - when using parted with qemu images

I have a Linux from scratch LiveCD running on qemu vm. I'm using this command to create a hda disc for qemu: qemu-img.exe create -f qcow2 base-linux.img 5G Then I run my vm: qemu.exe -m 1024 ...
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2answers
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free up not used space on a qcow2-image-file on kvm/qemu

we are using kvm/qemu with qcow2-images for our virtual machines. qcow2 has this nice feature where the image file only allocates the actually needed space by the virtual-machine. but how do i shrink ...
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0answers
23 views

Set custom cpu string for qemu/kvm

I have some virtual machines with software, which licensing check depends on cpu string. They're running on kvm - with default cpu string value - which is QEMU Virtual CPU version 1.7.1 After ...
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2answers
823 views

Extremely slow qemu storage performance with qcow2 images

I'm running some images using libvirt on a small Openstack cluster. Storage performance on these machines is extremely poor: my monitoring tool shows 100% utilisation (usually on writes but sometimes ...
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1answer
52 views

Prevent hijacking IPs in KVM/libvirt

How can I prevent a VM user/client from accessing IP addresses he doesn't own but are routed over the same bridge on KVM/Libvirt? IP addresses are routed to a cisco switch vLan consisting of a /24 ...
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1answer
38 views

How to make sure qemu-img resize does not lose data?

I'm trying to understand how qemu-img resize shrinks the virtual disk. Let's say qemu-img info shows that the virtual size is 20G, and the disk size is only 1G. Now I want to shrink the disk from 20G ...
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1answer
354 views

qemu-img snapshot on live VM

I have created multiple KVM VMs using QCOW2 images. Each VM has its own qcow2 file and is not based on any backing file. My question is specifically related to snapshots of QCow2 images on these ...
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23 views

virsh adding x2apic, cache specific options to kvm config

Anybody know the syntax how to add +x2apic to the virtual machines xml files when I edit them with "virsh edit vm"? From the command line it would be starting with this flag: qemu -cpu ...
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1answer
41 views

QEMU multiple port forwarding

I would like to forward more than one port. This command run my VM and forwards RDP port successfully: qemu-system-i386 -net nic,model=rtl8139 -net user,hostfwd=tcp::3389-:3389 -m 512M -localtime ...
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89 views

qemu with network namespaces and openvswitch

I want to put each qemu process in its own network namespace. However when I do this I cannot get bridged networking to work. This doesn't use namespaces, but makes qemu work with ovs: ovs-vsctl ...
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121 views

QEMU USB passthrough is not working

I stuck at getting USB passthrough working with Windows 8.1 guest OS on Ubuntu Server 14.04. I started by installing qemu using the Ubuntu Documentation (https://help.ubuntu.com/community/KVM). The ...
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1answer
68 views

kvm/qemu host windows guest BSOD about driver_irql_not_less_or_equal for viostore.sys

I have a KVM/Qemu host running 4 Windows Server 2012 guests and after upgrading the host from Ubuntu 12.04 to 14.04 I get blue screens with a bug check string of "driver_irql_not_less_or_equal" that ...
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1answer
21 views

enable vnc after virt-install

I've created a virtual machine using virt-install with graphics --none. I want to enable vnc. I've tried virsh -c qemu:///system qemu-monitor-command vm171-SC-1 --hmp change vnc :3 but it doesn't ...
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2answers
22k views

Difference between KVM and QEMU

I have been reading about KVM and Qemu for sometime. As of now I have a clear understanding of what they do. KVM supports hardware virtualization to provide near native performance to the Guest ...
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1answer
166 views

Qemu+libvirt+kvm significant performance lag in VM's

I am troubleshooting poor performance on our new VM host machine which is a Dell PowerEdge R415 with hardware RAID. We've got about 20 VM's running like this: qemu-system-x86_64 \ -enable-kvm \ ...
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1answer
141 views

Unable to import Ubuntu virtual machine on Centos 7 kvm host

[root@kvm ~]# virsh create /root/ns1.jesse64.xml error: Failed to create domain from /root/ns1.jesse64.xml error: internal error: process exited while connecting to monitor: qemu-kvm: -machine ...
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1answer
68 views

Convert virtual disk image to physical disk?

I'm trying to use QEmu for Windows to convert a virtual disk image to a physical SSD. But I'm not sure about the syntax for the output_filename parameter. Here's what I tried: qemu-img convert -p ...
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3answers
2k views

How to efficiently share host's folder with KVM guests?

I am configuring the service which stores plenty of files uploaded by nginx in /srv/storage dir on host system. These files are processed by worker KVM guests which may create new files or assign ...
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139 views

qemu-img VHD to raw image convert results in bad geometry:

Is anyone else able to reproduce this? Using StarWind V2V Image Converter on Windows, I'm able to get a valid disk.img file, so the source image.vhd is clean (pulled down from rackspace). Is this a ...
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libvirt hook qemu suse12

we have this qemu hook. In suse 11 was working well but in suse 12 it is not working. The hook is setting the ports in openvswitch native-untagged. Do you know if there is some libvirt missing ...
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119 views

OpenNebula glusterfs cannot create on volume

I try to create a VM on my gluster volume, it fails with the following message: Wed May 20 20:37:30 2015 [Z0][DiM][I]: New VM state is ACTIVE. Wed May 20 20:37:30 2015 [Z0][LCM][I]: New VM state is ...
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1answer
117 views

How much of a performance does using QEMU virtualization incur on Windows?

How much of a performance does using QEMU virtualization incur on a Windows host, when both the host and vm are running the same CPU? Older articles indicate that using kqemu avoided the slow down in ...
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3answers
81 views

Version control for virtual disk images

Is there any existing system for efficiently tracking the version history of a virtual disk image? Essentially, I have a disk image which is used as a "template" root filesystem for testing programs. ...
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1answer
321 views

Enabling Qemu/KVM Filesystem Passthrough Centos 7

I have a system running Centos 7 with the stock qemu/KVM code. I have several virtual servers running on this system and would like to enable the filesystem passthrough option. So far, I have not ...
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0answers
87 views

Why are Windows XP and 7 qemu/kvm guests not recognizing updates to a local Samba share?

I develop cross-platform software and test the Windows ports with wine, Windows XP, and Windows 7, the latter two tested using qemu with KVM. I also have several versions of OS X and Debian Wheezy as ...
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1answer
2k views

Any way to convert qcow2 to ovf?

In our application we are downloading a qcow2 image and after that we are supposed to import that as OVF. So any way to convert qcow2 --> OVF or qcow2 --> vmdk(using qemu-img convert) --> ...
0
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1answer
319 views

How to configure and use qemu-guest-agent in Ubuntu 12.04? My main aim is to get the IP address of guest VM from Host machine

In the documentation it is not very clear that how to install and use qemu-guest-agent in Ubuntu 12.04. So can anyone help me out ? http://wiki.libvirt.org/page/Qemu_guest_agent It is a daemon ...
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2answers
2k views

How to speed up QEMU on Windows host?

We want to run our Ubuntu 64bit web server virtualized/emulated on a Windows 64bit host. Intended use is to distribute the VM to customers who might not have "elevated" or "admin" rights on the ...
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2answers
31 views

I added space to a kvm img file but the physical extents do not show up in lvm

I ran qemu-img resize kick.img +12G and thought I'd see some free physical extents when running pvdisplay but nope. When I run virt-filesystems --long --parts --blkdevs -h -a kick.img I see the space ...
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1answer
125 views

CentOS Qemu+KVM lot of virtual machine processes

I am on host-machine with Centos 6.5, qemu+KVM and 2 virtual hosts in it (behind NAT). Both virtual hosts were configured with Virtual Machine Manager (one of them is with Windows 2003 and other with ...
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1answer
5k views

Read/write access for passthrough (9p) filesystems with libvirt/qemu?

I have recently started experimenting with the support for passthrough filesystems in recent versions of KVM/QEMU/libvirt. Making the filesystems available for read access has "just worked", but I'm ...
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1answer
44 views

libvirt management is slow under ubuntu

I've just done a fresh install of KVM/Qemu under Ubuntu 14.04.2 on an older (C2D gen) server with dual quad core xeons and 24 gb of ram. I'm finding that I'm waiting for operations in virsh for around ...
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0answers
127 views

KVM GPU passthrough working only with cirruslogic vga added, VM goes in paused state if remove cirruslogic and boot with passed-through gpu only

It seems I had this working once but maybe that was when my kernel wasn't trying to load the fglrx kernel module. (I think before it was loading 'radeon' module) Not sure if this was the issue/change ...
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3answers
637 views

attaching usb dongle to KVM VM

I'm struggling to connect a usb device, that gets detected correctly by the host, to a kvm vm. I have a freshly installed Ubuntu Server 14.10 as KVM/QEMU host. I set up an Ubuntu vm using this ...
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392 views

qemu-kvm fail to boot Centos 5.3 after Kernel update at the host (feodra)

After updating Fedora 18 to kernel 3.9.x (current 3.9.4), I can no longer boot my Centos 5 guest OS. When I try to boot, the process halt at start and the CPU core work at 100%. If I boot Fedroa ...