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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kvm and qemu host: Is there a limit for max CPUs (Ubuntu 10.04)?

Today we encountered a really strange behaviour on two identical kvm and qemu hosts (Dell R910). The host systems each have 4 x 10 Cores, which means that 40 physical cores are displayed as 80 within ...
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3answers
2k views

Is there a way to determine which virtual interface belongs to a virtual machine in a kvm host?

I'm using qemu/kvm whith bridged networking. In the host machine there are several "vnetX" network interfaces without IP. I'm looking for a way to know which vnetX belong to a virtual machine. I ...
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312 views

qemu/virt-manager no permisson on shared folder

I have a strange problem. Iam trying to create a shared folder via the add-hardware->filesystem option. For Type and Modus i choose Passtrought and for Driver Path. The Source Path is /free and target ...
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1answer
374 views

How to connect a virtual NIC in one QEMU-KVM instance to a virtual NIC in another QEMU-KVM instance without a bridge

Is there a way to connect a Virtual NIC one QEMU-KVM instance to a Virtual NIC on another QEMU-KVM instance. I want to be able to do this efficiently and it may be possible that the 2 instances could ...
2
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1answer
426 views

qemu with tun virtual networking issues

I'm trying to setup a virtual networking environment using open-wrt qemu and vde2 The script to boot two qemu instances and conenct them together is the following ...
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2answers
1k views

understanding relationship between Qemu and KVM

What is the difference between KVM and Qemu? As I understand, latter is able to provide "user mode emulation" which means that one can run a single executable built for some other architecture like ...
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2answers
4k 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
393 views

Routing table with two NIC adapters in libvirt/KVM

I created a virtual NAT network (192.168.100.0/24 network) in my libvirt and new guest with two interfaces - one in this network, one as bridged (10.34.1.0/24 network) to the local LAN. The reason for ...
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2answers
170 views

How to delete the MBR (Master boot record) out of an image file?

I have a QEMU image myserver.img that is about 20GiB. The file serves as a "virtual" hard disk for the server. Now the first 512 bytes contain the MBR, and I am trying to overwrite those bytes with ...
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1answer
271 views

FVD format on qemu/KVM

How can I install this format in Centos KVM?. Is it included in latest qemu versions? Reference in qemu wiki: http://wiki.qemu.org/Features/FVD Thanks in advice
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2answers
182 views

Host Websites on Virtual IP VMs

I have Proxmox Virtulization server installed. But i have one real(Public) IP. Incoming request to Proxmox server must be bind Virtualized servers. Dnsmasq installed in Proxmox Virtualization Server. ...
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3answers
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QEMU-KVM Linux virtualization on the command line

I recently discovered that qemu-kvm has a very promising -curses option that, instead of starting an X window, will show a nice ncurses output from the guest suitable for managing a Linux guest from ...
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2answers
143 views

Managing a QEMU guest from the host's CLI

Can I manage a QEMU guest from the host's CLI? I'm coming from Xen and I liked the xm command. I'd like to shutdown the guest, attach PCI devices to it and so on. Is there a way? There's the QEMU ...
5
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1answer
796 views

TCP/IP performance tuning under KVM/Qemu

With more and more companies switching to public cloud services, I'm curious what you guys' thoughts are on TCP/IP tuning in the cloud. Is it worth bothering with? Given that you don't have access to ...
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1answer
497 views

QEMU virtual networking NAT

I'm trying to set up a virtual network as described here. These are my steps: ifup eth0 # uses DHCP brctl addbr br0 ifconfig br0 up 192.168.0.1 kvm ... -device e1000,netdev=tap0 -netdev ...
9
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1answer
3k 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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2answers
1k views

How to quit QEMU monitor?

I launched KVM VM with this command: kvm /kvm/hdd/v1/v1-1.raw -m 512 -daemonize -smp 2 -nographic -net nic,model=virtio,macaddr=aa:aa:aa:aa:aa:01 -net tap,ifname=tap0 -monitor ...
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1answer
566 views

Fault-tolerant KVM hosts

I'm going to create a simple virtual hosts infrastructure using QEMU+KVM. It is expected to be very simple, without clouds or any other cool things. Right now the only requirement is the ...
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2answers
314 views

Software for managing a cluster of KVM physical hosts?

I am looking for software recommendations for managing a cluster of KVM physical hosts. We are currently using virsh and doing just about everything by hand, and I would like to find a slightly more ...
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0answers
171 views

QEMU Remote Access on Xen Guest

I have an Ubuntu Server install which is running as a Xen guest on a VPS. I am looking to emulate something somewhat similar to SUSE Studio's test-drive feature which allows a VNC-style connection in ...
2
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2answers
2k views

qemu-kvm/virsh: No network connectivity whilst using bridged networking

I'm having an issue with performing virtualisation via libvirt/qemu-kvm, in which my set up for bridged networking doesn't appear to be working correctly. I've followed every tutorial I can find and ...
0
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1answer
789 views

How to convert OpenVZ OS template to bootable image file?

My question is how to convert a pre-created OpenVZ OS template which are in tar.gz format (such as these) to an image file in order to be able boot it with other virtualization solutions such as QEMU ...
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62 views

virt-rescue for Ubuntu

I want to install virt-rescue on Ubuntu 11.10 or Ubuntu 10.04. It could not be found in the repositories. Where can I get it?
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1answer
228 views

freebsd iso install on KVM - timer freezes

Trying to boot freebsd iso on KVM/libvirt [debian host] Timer shows: 10 sometimes is 9 or even 7. and that's it, count down stops.. Found some information that it's a bug with newest qemu and my ...
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1answer
401 views

Installing and running a guest OS on KVM-qemu with only serial console access

I am trying to installing a bsd distro with virt-installer. With a Linux distro I used this: virt-install -n debian -r 1024 --vcpus=1 --accelerate -v --disk ...
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1answer
5k views

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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3answers
361 views

Store QEMU images in database

I have a task to store QEMU images in a database and thinking towards developing of the custom block device. Is this a good idea? Where is it better to start from?
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1answer
985 views

Qemu: can I set the serial number on a virtual SCSI device?

I'm using libvirt+KVM+Qemu on Ubuntu 11.04. I have some scsi devices like this: <disk type='file' device='disk'> <driver name='qemu' type='raw'/> <source ...
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1answer
356 views

Give a KVM Guest only access to OpenVPN

I'm in a kind of weird situation where I need to do the following: Connect an OpenVPN tunnel with static RFC1918 IPs (think of 10.3.3.1 for the server end and 10.3.3.2 for the client end) and have it ...
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2answers
6k views

Changing boot device for a QEMU-KVM virtual machine

I am trying to change the boot device for a VM. I go to the VM's XML file in /etc/libvirt/qemu and set <boot dev='cdrom' />. Still, it attempts to boot from the harddrive instead of the cdrom. ...
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1answer
958 views

How to add a serial COM port to Windows server 2008 using Linux + KVM + Qemu?

We are using Linux + KVM + Qemu with libvirt on our servers to manage virtual WIndows 2008 Servers. The Host is Ubuntu 11.04. The point is on one of our Windows server 2008 guest, we need to connect ...
2
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1answer
892 views

Set Mac Address in QEMU/KVM properties file

I'm trying to set the mac address for my virtual machine in the virtual machine properties file. The properties file '102.conf' currently looks like this: name: vm1.mydomain.com bootdisk: ide0 ...
5
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1answer
486 views

Maximizing throughput of virtual file systems

I've been using a QEMU system to build software. The problem I've been having is that the system seems to suffer from extremely slow disk access. This is not necessarily a problem as it's not really a ...
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0answers
474 views

qemu-img: preallocate portion of qcow2 copy-on-write image?

I'd like to create a copy-on-write qcow2 image on top of a read-only base image. However, the write performance of the copy-on-write top image is too slow for the intended workload. Is there a way to ...
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1answer
897 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
706 views

qemu-kvm save and restore in different machines - Offline migration

I am using KVM in cents 5.6. I am trying to do offline migration between two machines. I have a common NFS server. I initially save the state of the running VM (on machine1) to a state file using : ...
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1answer
1k views

CentOS 5.4 No package qemu available

I'm trying to install qemu on CentOS 5.4(final) with: yum install qemu The result is: Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile * addons: mirror.steadfast.net * ...
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1answer
724 views

KVM / QEmu / Libvirt I/O lockup

Simple issue. I'm running 5 KVM/QEmu instances. the host machine is constantly freezing for about a half a second in every 5. Disk LED hints that it is disk write related. Host is FC14, guests of ...
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1answer
1k views

Libvirt command line arguments using xml config file

I am trying something similar to http://wiki.libvirt.org/page/QEMUSwitchToLibvirt#-s . This is my xml file : <domain type='kvm' xmlns:qemu='http://libvirt.org/schemas/domain/qemu/1.0'> ...
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1answer
250 views

I cannot see any files after running qemu-img convert

I have run sudo qemu-img convert box-vmware-disk.vmdk -O raw /dev/sda1. No error was encountered all seems to have ended ok, but when I open the hard disk I cannot see any files. I want to be able to ...
2
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2answers
181 views

virtual interface names in qemu/kvm

I have an image with a debian-squeeze installation and using that I created two overlay-images to boot two (nearly identical) virtual machines from. When I boot them up individually (connecting them ...
0
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1answer
735 views

Using qemu-kvm images with Mac OS X?

i am a big fan of qemu-kvm, i've several instances running on servers running ubuntu linux. I now wonder if it's anyhow possible to use a virtual server image on an Mac OS X machine. Either by running ...
0
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2answers
439 views

9p filesystem interacting badly with KVM savevm snapshot

I have a 9p mount inside a VM. I take a snapshot of the VM state with savevm <snapshot>, stop the VM, then restart it with that snapshot (with kvm -loadvm <snapshot>). When I try to ...
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2answers
630 views

Why is KVM Host server CPU utilization very high, when the windows guest is idle?

I have Win 2008 running on a Ubuntu 10.04 host using KVM/QEMU. The version is 0.12.3. Event thought the Win 2008 is idle (no updates, most services are turned off), on the host server one of the core ...
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2answers
662 views

is it possible to install qemu inside linux ami on ec2?

well i tried to install it but gont an error . kernel-2.6.35.11-83.9.amzn1.i686 has missing requires of mkinitrd >= ('0', '6.0.91', None)
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1answer
233 views

Guest Access in QEMU-KVM

I am having trouble in accessing my Guest OS running on QEMU-KVM. However, I noticed that the Guest OS is capable of accessing Host OS easily thru telnet; basically every IP address appear in ifconfig ...
2
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1answer
226 views

KVM QEMU looses USB devices

I have a KVM Qemu setup. I'm mapping a USB device to a VM running windows vista. I get the device mapped, and all is well for some time. Suddenly the device disappears in Vista. If I do "lsusb" in ...
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3answers
3k views

Convert directory to QEMU/KVM virtual disk image

I have a directory filled with data at /var/backups/disk1 that I want to convert into a virtual disk image which I'll then be able to boot using QEMU or KVM (the directory contains the file system for ...
0
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1answer
574 views

Error: running qemu on powerpc

I have installed qemu-0.13.0 on x86 system. I downloaded debian-powerpc image from http://people.debian.org/~aurel32/qemu/powerpc/ and used it with this command $qemu-system-ppc -hda ...
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3answers
2k views

How to migrate KVM based VMs running in LVM setup to Vmdk images

I am using KVM on Ubuntu Server 10.04. and Virtual Machines are running on it in LVM. I have to migrate some of them to Vmware server.How can I achieve this? I searched and came across some links but ...