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.

learn more… | top users | synonyms

1
vote
3answers
436 views

Opening a Qemu/Xen file based VM Image (won't boot after upgrade)

Apart from one Virtual Host still running Xen/RHEL5, all our virtual capability is hosted on KVM hosts with LVM storage devices. I've stupidly attempted an Ubuntu full release upgrade on a guest ...
6
votes
1answer
991 views

KVM/Qemu, Ubuntu: Why do more guests CPUs enhance Disk-I/O rapidly?

We have an Heartbeat/DRBD/Pacemaker/KVM/Qemu/libvirt cluster consisting of two nodes. Each node runs Ubuntu 12.04 64 Bit with the following packages/versions: Kernel 3.2.0-32-generic #51-Ubuntu SMP ...
0
votes
1answer
457 views

Can't get network bridging to work

I'm trying to make network bridging to work on a Debian squeeze (I'm experimenting in order to make a QEMU/KVM virtual machine that will be visible to the outside network as if it were a distinct ...
4
votes
0answers
557 views

QEMU: Solaris 11 / Sparc64 Guest on Linux / X86-64 Host [closed]

I'm trying to run a Solaris 11 / Sparc64 guest on a Linux/x86-64 host. I've cloned the qemu project and configured/compiled it with sparc64 support (./configure --target-list="sparc64-softmmu"). I've ...
2
votes
1answer
130 views

Install Windows with QEMU

I want to understand if it is possible to install Windows from Qemu to a physical HDD. I was trying to do that by doing something like this: qemu-system-x64 -m1024 -vnc :1 -hda /dev/sda -cdrom ...
-2
votes
1answer
357 views

Qemu on Mac instead of VirtualBox [closed]

Assuming I only want to use Linux as guest, are there any advantage in using Qemu instead of VB or other commercial solutions such as VM Fusion? I want to easy to ro tun Linux on my Mac without too ...
0
votes
2answers
180 views

make vnc server listen on guest's ip address

My host system has the IP 192.168.0.250. Now I want to create a kvm guest using a tap device (so the network card of the guest just acts like a "real" one). The guest has a static ip 192.168.0.249 ...
2
votes
2answers
153 views

kvm process has too large a memory footprint on host

I'm using latest ubuntu quantal and start a kvm guest which should have 2048 MB of memory. Now after a few hours I can see that the kvm process of this guest is around 2700 MB, so 700 MB more than the ...
0
votes
1answer
944 views

kvm with virtio scsi and rbd

I'm currently using virtio-blk but I'd like to change to the new virtio-scsi, especially because it supports trim/ discard. The host is an ubuntu quantal system (kernel 3.5.0, qemu 1.2.0). This is ...
2
votes
2answers
2k views

qemu-img: Could not open $FILE

I received a single-file VMDK from a vendor that has a virtual appliance for a particular product I'm interested in evaluating. We run a KVM solution (Proxmox) so I tried converting the file but on ...
0
votes
2answers
1k views

KVM/Qemu Guest Shutdown problems

on both host and guest running CentOS 6.3 with KVM/Qemu virtualization, I have the following scenarios: "virsh shutdown kvm1" did not shutdown at all. virsh lists guest as running. "service ...
5
votes
2answers
136 views

Accessing the partitions on an LVM volume

Suppose you have an LVM volume /dev/vg0/mylv. You have presented this as a virtual disk to a virtualised or emulated guest system. During installation the guest system sees it as /dev/sda and ...
-1
votes
1answer
444 views

Is it possible to pass /dev/urandom through from the host to a qemu/kvm guest?

I'd like to pass the host's /dev/urandom device through to a qemu/kvm virtual machine. Note that /dev/urandom is not seekable, so it's not possible to pass it through as a block device using -hda, ...
0
votes
2answers
3k views

Is there any way to shrink qcow2 image without converting it raw?

Is there any way to shrink qcow2 image without converting it raw? I cannot convert it to raw because I don't have disk space enough for raw image.
1
vote
1answer
174 views

Is it possible to run Windows as a Xen VM without VT, using Qemu-dm?

Is it possible to run windows as a virtual machine under Xen using qemu-dm? If so, how can it be done? Since Xen without VT technology supports only para-virtualization, can qemu-dm, the emulator ...
3
votes
2answers
7k views

conversion of a VMDK image with qemu-img failed with “error while reading sector 131072: Invalid argument”

I tried to convert a VMDK image found in a OVA file to the QCOW2 format with the qemu-img command but it failed with the error message qemu-img: error while reading sector 131072: Invalid argument ...
1
vote
2answers
2k views

does KVM raw images support preallocation?

I was trying to create a raw image with this command: qemu-img create -f raw -o size=200G,preallocation=metadata file.img but seem that it raw images doesn't support preallocation. if so why there ...
0
votes
1answer
257 views

KVM low network speed

I have a networking problem with KVM. There is only one VM on the server and port speed is 100 megabits per second But maximum download rate is about 1 megabytes per second and expected to be 10mb. ...
0
votes
2answers
726 views

Share CPU between two KVM VPS on a dedicated server

how can I share CPU between two KVM VPS on a dedicated server? assume that we have 8-core CPU on a dedicated server to get maximum performance for two VPS, should I assign 8 cores to each one of ...
0
votes
2answers
671 views

How to create LAN segments in qemu

I could successfully connect two different virtual machine ports directly using LAN segment feature in VMware workstation. Is there a way to do the same on qemu ? As of now i have created two qemu ...
0
votes
1answer
850 views

CentOS libvirt reboot

I've noticed the following status message after system update (on SL 6.1 - yum update): # /etc/init.d/libvirtd status libvirtd dead but pid file exists one of the updated packages was "libvirt". ...
0
votes
1answer
3k views

Libvirt / QEmu Machine Fails and Refuses Restart Because of Memory Allocation Errors

I'm having a problem with libvirt. On a system restart all virtual machines (VMs) are started without a problem and keep running. Then at some point in time a set of machines shuts down according to ...
12
votes
4answers
23k views

KVM: Which CPU features make VMs run better?

We are using Ubuntu 12.04 with the following parameters: Dell R910 Kernel 3.2.0-25-generic #40-Ubuntu SMP x86_64 x86_64 x86_64 GNU/Linux kvm 1:84+dfsg-0ubuntu16+1.0+noroms+0ubuntu13 qemu-kvm ...
1
vote
2answers
354 views

QEMU Virtual CPUs

I've seen that people run VMs with KVM and QEMU Virtual CPUs but when I'm creating a VM using virt-manager it only show my real cpu cores not virtual CPUs. how can I activate QEMU Virtual CPU? Thanks ...
5
votes
2answers
1k views

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 ...
2
votes
3answers
3k 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 ...
1
vote
1answer
345 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 ...
2
votes
1answer
502 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
votes
1answer
530 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 ...
13
votes
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 ...
7
votes
2answers
5k 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 ...
0
votes
1answer
472 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 ...
1
vote
2answers
173 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 ...
1
vote
1answer
302 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
0
votes
2answers
190 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. ...
5
votes
3answers
2k views

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 ...
2
votes
2answers
148 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
votes
1answer
915 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 ...
0
votes
1answer
602 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 ...
10
votes
1answer
4k 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 ...
7
votes
2answers
2k 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 ...
0
votes
1answer
630 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 ...
0
votes
2answers
335 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 ...
2
votes
2answers
3k 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
votes
1answer
900 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 ...
1
vote
0answers
78 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?
1
vote
1answer
244 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 ...
2
votes
1answer
471 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 ...
8
votes
2answers
6k 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 ...
0
votes
3answers
369 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?