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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17
votes
2answers
13k 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 ...
17
votes
3answers
6k views

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 ...
11
votes
6answers
26k 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 ...
8
votes
3answers
16k 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 ...
166
votes
3answers
148k 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 ...
30
votes
6answers
43k 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 ...
25
votes
3answers
72k 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 ...
22
votes
5answers
90k 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+...
12
votes
5answers
12k 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 ...
18
votes
2answers
6k 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 ...
9
votes
1answer
2k 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 ...
3
votes
4answers
6k 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: ...
5
votes
1answer
18k 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 "...
5
votes
1answer
23k 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) --> ...
4
votes
2answers
19k 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 ...
0
votes
1answer
3k 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
1answer
1k 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'> &...
5
votes
1answer
5k views

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 ...
4
votes
0answers
2k 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 ...
4
votes
3answers
1k 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=...
3
votes
1answer
1k 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 ...
2
votes
1answer
524 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":{"...
1
vote
1answer
1k 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?
1
vote
1answer
806 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 ...
1
vote
2answers
2k 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. ...
1
vote
3answers
5k 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 ...
0
votes
1answer
2k 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 ...
0
votes
1answer
2k 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'...