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.

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host port forward with qemu through libvirt in user-mode networking

I'm having trouble editing my libvirt's host-xml to make qemu forward TCP connections to the guest. This questions linked to a blog post which recommended adding -redir to the Qemu command line. But ...
Frederick Nord's user avatar
17 votes
2 answers
17k 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 ...
larsks's user avatar
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17 votes
3 answers
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KVM guest cannot write to 9p share owned by non-root

I am aiming to set up full write access to a 9p share for a KVM guest. Both host and guest have the same users/groups with the same IDs. Both host and guest should be able to write to the share using ...
Greendrake's user avatar
  • 1,421
13 votes
6 answers
39k 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 ...
Chris's user avatar
  • 131
9 votes
3 answers
20k 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 ...
csch's user avatar
  • 199
205 votes
3 answers
181k 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 ...
Abhishek Gupta's user avatar
37 votes
6 answers
61k 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 ...
bmaeser's user avatar
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30 votes
3 answers
97k views

How to start qemu directly in the console (*not* in curses or SDL)

I seem to recall being able to start qemu with only the terminal emulator output, with the graphic window disabled. And here I don't mean with the ncurses interface, that one is nice, but I want the ...
anarcat's user avatar
  • 794
22 votes
5 answers
98k 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 1.0+...
PythonLearner's user avatar
20 votes
2 answers
7k 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 ...
Martin's user avatar
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13 votes
1 answer
38k views

KVM gets stuck at "Booting from hard disk"

I am trying to run Ubuntu-server-16.04 virtual machine on a KVM converted from .vhdx (Hyper-V) to .qcow2 (KVM). When I import my virtual disk image and start virtual machine, the KVM hangs on "...
Miodrag's user avatar
  • 131
12 votes
5 answers
18k views

Solidworks: activation license mode is not supported in this virtual environment (Qemu-KVM)

The question is not around Solidworks actually, so please continue to read. The whole idea of virtualization is to be hardware independent. Before our eyes a whole new dependency level is being ...
Michal Sokolowski's user avatar
9 votes
1 answer
3k 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 ...
PythonLearner's user avatar
5 votes
1 answer
28k 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) --> ...
Reuben's user avatar
  • 167
5 votes
3 answers
2k views

Migrating physical machine to KVM

I have a fairly old debian machine that I need to migrate to KVM-Qemu. What I started is to make a tarball of the root filesystem: tar -cpf rootfs.tar --exclude='dev/*' --exclude='proc/*' --exclude=...
qemu55's user avatar
  • 51
4 votes
0 answers
3k 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 ...
roylaurie's user avatar
  • 141
4 votes
2 answers
23k 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 ...
Erik Sjölund's user avatar
3 votes
4 answers
7k views

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: ...
user avatar
3 votes
1 answer
2k views

enabling virtualization on supermicro board

I'm trying to setup a virtualization server on an old Supermicro board (mainly for experimenting a bit), using qemu/kvm (running on Debian/jessie, with a 3.16.0-4-amd64 kernel) The board is equipped ...
umläute's user avatar
  • 519
2 votes
1 answer
2k views

Migrate a QEMU/KVM VM from qemu:///system to qemu:///session

I have a created a Windows 10 VM using virt-manager as user (not root). However, when try to list the VMs with virsh list --all, My VM is not listed? And, if I specify the system URI with by running ...
Adel M.'s user avatar
  • 121
2 votes
1 answer
1k views

QEMU cannot find device nor node_name

When I do virsh list I get ubuntu14.10 and ubuntu15.10 running but when I run this command to take a snapshot. virsh qemu-monitor-command ubuntu15.10 '{ "execute": "transaction", "arguments":{"...
Douglas Turner's user avatar
2 votes
3 answers
5k views

Create iPXE UEFI bootable image for QEMU/Libvirt with custom next-server and filename

I can create a VM with libvirt/qemu to boot in UEFI mode. I know that it does iPXE by default, but I want to create/modify a iPXE image in order to override filename and next-server properties. How ...
djuarezg's user avatar
  • 141
1 vote
1 answer
239 views

Windows asking me to sign in with a company email?

Windows is asking me to sign in with my company's email, problem is I don't have one and nor is the company related to me whatsoever. I am trying to run Windows LTSC on QEMU. What gives?
Anm's user avatar
  • 203
1 vote
1 answer
2k views

Ubuntu 22 No ACPI DMAR table found, IOMMU either disabled in BIOS or not supported by this hardware platform on nested VM

I am using ubuntu 22.04 LTS minimal server. My host server is set up with kvm and is functioning well. All tests pass when running virt-host-validate. When I create. virtual machine i want this to ...
shorif2000's user avatar
1 vote
1 answer
1k views

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 ...
sixpi's user avatar
  • 13
1 vote
2 answers
3k views

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. ...
LazyBrush's user avatar
  • 141
1 vote
1 answer
4k views

Use Thin LVM Volume for KVM VM

I now we cannot use thin LVM volumes with libvirt. Is there any other alternative allowing use of LVM thin provisioning in KVM/QEMU virtual machines?
user878965's user avatar
1 vote
3 answers
6k 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 ...
Bond's user avatar
  • 831
0 votes
1 answer
5k views

KVM QEMU Guest VMs randomly lose network connection

I'm working on setting up a server with KVM/QEMU and all Linux servers. We are going to use this server for web development, git, VoIP PBX, etc. (We were using XenServer and Windows Server 2016, but I'...
ZhangXector's user avatar
0 votes
1 answer
4k views

Centos 7, Qemu virtualization: Win10 guest VM very slow after Windows Update

We use qemu virtualization for many years now! It's a great tool! We use it both for Linux VM’s and Windows VM’s! It's the first time we have any issues and I have no clue on where to find the ...
Enovator's user avatar
0 votes
1 answer
2k views

How to mount a URL as a CD-ROM on QEMU?

I'm wondering if it's possible to specify a URL for the cdrom option on QEMU, and if so how would I go about doing that? Normally I'd mount an iso like this: <disk type='file' device='cdrom'> &...
Bravo Delta's user avatar
0 votes
1 answer
4k 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, -...
Dustin Kirkland's user avatar