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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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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41 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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45 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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35 views

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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34 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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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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22 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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51 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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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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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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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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84 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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116 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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1answer
165 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
138 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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34 views

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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1answer
66 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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135 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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115 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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115 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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314 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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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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350 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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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
124 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
43 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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126 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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What is the maximum number of VM which can be used for a single baseimage? [duplicate]

In my current project I am using KVM hypervisor and qcow2 as a base image. On that base image I am creating many VMs, say 100s of VMs. So, my question is that will that baseimage be a bottleneck for ...
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Which is better image format, raw or qcow2, to use as a baseimage for other VMs?

I am using a baseimage and based on that creating many VMs. And now I want to know which is better, qcow2 or raw to use for a baseimage. Moreover, can you please tell me if there is any advantage of ...
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1answer
92 views

Revert libvirt external snapshot

Having some issues understanding how to revert snapshots on ubuntu 14.04 using KVM... Until now i have been using internal snapshots, however due to space issues (space not being re-allocated after ...
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2answers
810 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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337 views

Backup KVM running machine safely

I read some solutions to make backups of running VMs, but all take offline snapshots that seems difficult that will work if the VM has high I/O load. I have tested but i have doubts about the process ...
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1answer
187 views

Qemu Proxmox VM - Network access to guests for BackupPC backups

Environment I rent a dedicated server from OVH and installed Proxmox 3.3 (which is based on Debian 6 Wheezy) in order to create and manage multiple Virtual Machines on it. Each VM is configured to ...
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1answer
318 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
160 views

How to measure boot time of a VM from host machine?

On both Guest machine and host machine, I am using Ubuntu 12.04. As a hypervisor I am using KVM. I want to perform some experiments related to boot-storm and I have created all other scripts to ...
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3answers
634 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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180 views

QEMU/KVM port forwarding issues

I'm trying to access websites hosted on a QEMU/KVM debian virtual machine from a Ubuntu host machine and other PCs/devices on the host machine's network. Later, I'd like to access this from the ...
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1answer
307 views

Extremely slow disk IO in qemu-kvm VM

I have a VM running Debian Woody (kernel 2.4.18). Qemu-2.1.2, 2 CPU cores, 512M RAM, qcow2 image connected as IDE, ext3. The issue is that disk IO is slow. Here is a result of dd "benchmark" right ...
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149 views

Force libvirt to pass always the same device number to the guest on USB device reconnection

I have a HP plotter connected with a USB cable to a debian server through a USB hub. On the server there is a virtualized Windows XP. Everytime I reboot the plotter a different device number is ...
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105 views

gluster libgfapi HA

I was exploring KVM_qemu with gluster distributed storage. My goal was to build a test cluster with complete HA . i.e HA for VMs as well as gluster storage . I'm planning to setup a 3 node gluster ...
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1answer
174 views

Changing qemu/libvirt default gateway IPv4 IP to something other than x.x.x.1/24

General info: I have a KVM-libvirt/qemu running on ArchLinux; 3.18.2-2-ARCH ls | egrep -i 'libvirt|qemu' libvirt-1.2.11-1-x86_64.pkg.tar.xz libvirt-glib-0.2.0-1-x86_64.pkg.tar.xz ...
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58 views

QEMU stop/continue memory releasing

When using qemu-monitor console, i do PAUSE / CONTINUE of different VMs with stop/cont commands, which works ok, and my main CPU usage stays low. Is it possible to keep memory usage low this or ...
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27 views

mounting logical volume attached to vm while vm is running

i am experimenting lvm2 and qemu-kvm. and I want to share and ask some questions. at the end of there is appendix what i am doing. a logical volume on host is attached on guest host (vm) as vda. this ...
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405 views

virt-install fully automated install

I'm looking into ways of installing/deploying a VM completely automated (no user interaction). So far I have tried QEMU and virt-install along with QEMU. The issue with qemu is that injecting ...
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1answer
107 views

Qcow2 images growing far beyond what they should

I am using ubuntu 12.04 and have seen this: https://bugs.launchpad.net/ubuntu/+source/qemu-kvm/+bug/1025244 Our qcow2 images are growing far beyond what they should... with some of them growing to as ...
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91 views

Why ssh tunnel cannot create in the virtualbox or qemu with force mode (-f)?

I try on the dedicated server root@debian:~# strace -e open -f sshpass -p guest ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null guest@198.51.100.11 -C -N -D 127.0.0.1:22220 -f [pid ...
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222 views

qemu, kvm: Guest: No DHCPOFFERS received

I'm trying to set up a virtual machine (guest) wich should act as router (ubntu 14.04). The host is a CentOS 7 machine (4x LAN). The guest should get a public ip address over it's eth0 (guest), wich ...
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487 views

Linux QEMU issue with bridge network interface

I am trying to setup a bridge interface for one of my QEMU running on CentOS 7. I have below scripts for TAP interface running $ cat /etc/qemu-ifup ifconfig ens192 down ifconfig ens192 0.0.0.0 ...