Server Fault Stack Exchange
Server Fault Stack Exchange

Questions tagged [qemu]

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.

QEMU has two operating modes:

  • User mode emulation

In this mode QEMU runs single Linux or Darwin/Mac OS X programs that were compiled for a different CPU. System calls are thunked for endianness and for 32/64 bit mismatches. Fast cross-compilation and cross-debugging are the main targets for user-mode emulation.

  • Computer emulation

In this mode QEMU emulates a full computer system, including peripherals. It can be used to provide virtual hosting of several virtual computers on a single computer. QEMU can boot many guest operating systems, including Linux, Solaris, Microsoft Windows, DOS, and BSD 1; it supports emulating several hardware platforms, including x86, x86-64, ARM, Alpha, ETRAX CRIS, MIPS, MicroBlaze, PowerPC and SPARC.

Source: wikipedia

637 questions
2
votes
0 answers

How to prevent conntrack overflow on host with many qemu guests

Is there any way to make iptables conntrack use separate data structures for each network interface? Would network namespaces help here (put each guest together with its tap device in its own netns and do the ipfilter conntrack inside that netns),…
gucki
  • 818
  • 2
  • 11
  • 29
2
votes
0 answers

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 qemu-img bug under RHEL/CentOS 7? ... any…
rickatech
  • 141
  • 8
2
votes
1 answer

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 performance if both host and vm used the same…
vfclists
  • 1,632
  • 5
  • 22
  • 37
2
votes
1 answer

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 had any luck. I have downloaded ther kernel…
Brent
  • 31
  • 1
  • 1
  • 4
2
votes
1 answer

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 use a public IP (given by OVH), configured as IP…
Danyright
  • 203
  • 1
  • 7
2
votes
2 answers

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 create VM, delete VM and start VM. But I don't know…
A-B
  • 573
  • 2
  • 7
  • 17
2
votes
2 answers

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 after VM reboot: (none):~# time dd if=/dev/zero…
Equidamoid
  • 121
  • 1
  • 4
2
votes
0 answers

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 assigned by udev to the plotter which has the effect to…
stenio
  • 163
  • 1
  • 1
  • 6
2
votes
0 answers

libvirt / kvm guests take very long time to start after host reboot

Host system is CentOS 6.5 x86_64. I have setup an Ubuntu guest by following this wiki. The guest works, but: if I reboot the host, it takes a very long time (about 30 minutes on the last reboot) before the guests actually start. If, during this…
Matt
  • 1,047
  • 2
  • 14
  • 20
2
votes
1 answer

qmp-shell doesn’t recognize commands

So, there is a python script that allows to connect to QEMU monitor from a usual shell. I had to download a bunch of files from the QEMU source tree, and add -qmp unix:./qmp-sock,server,nowait to the vm command line. It connects, but I can’t get it…
tijagi
  • 427
  • 2
  • 6
  • 16
2
votes
2 answers

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 startup I have set ip_forward to 1 Iptables is…
htfree
  • 483
  • 4
  • 9
  • 21
2
votes
4 answers

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. I occasionally need to make changes to it (e.g.…
floppusmaximus
  • 21
  • 2
2
votes
2 answers

Qemu: issues with bridged networking (Linux host, OpenBSD guest)

I have a computer running Linux. It has qemu installed. It has a bridge interface br0 configured with the following settings: IP: 10.1.1.1 Netmask: 255.255.255.0 There is also a tap0 interface that is added to br0. tap0 is supposed to be used for…
Anonymous
  • 1,550
  • 1
  • 14
  • 18
2
votes
0 answers

What could cause linux to reboot even though panic is not set

Bit of context. Few VM's running on KVM (SmartOS), using kernel 2.6.32.7 have been rebooting. Nothing in the Qemu/KVM logs to suggest it's a Qemu issue. Unfortunately while testing kdump i discovered a problem that causes the kdump kernel to panic…
Steven Williamson
  • 170
  • 1
  • 6
2
votes
1 answer

how to connect multiple kvm/qemu VM guests in to a subnet

I want to setup a simple subnetwork of KVM/QEMU guest VMs living on a single host (Fedora 19) for testing purposes. The subnet would contain 3 servers: 1 Debian 6.x eth0 ip: 10.0.0.7 eth1 ip: 10.0.2.1 2 Debian 7.x eth0 ip: 10.0.2.2 2…
b1tH1de0
  • 31
  • 2
  • 5
1 2 3
…
42 43