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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KVM: What is stored in var/lib/libvirt/qemu

My Question is "What is stored in the /var/lib/libvirt/qemu folder?" Is this used as somekind of backup folder ? Backgroundinformation: I have a Debian Server with a running KVM installation(+libvirt)...
KVMUser123's user avatar
4 votes
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Route QEMU VM traffic through hosts VPN

tl;dr Host connects via VPN to the internet and a VM on this host doesn't go through this VPN (but it should). I think the network config isn't quite correct. The host The host (arch Linux) connects ...
theo_retiker's user avatar
4 votes
1 answer
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QEMU versatilepb default network adapter

I'm using qemu to emulate a raspberry pi. I'm starting qemu like this: qemu-system-arm -kernel ./qemu-rpi-kernel/kernel-qemu-4.1.13-jessie \ -cpu arm1176 -m 256 -M versatilepb \ -append "...
Tom's user avatar
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4 votes
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Libvirt & USB Hub Passthrough

I have a virtual machine which I wish to have a USB Hub and all of its devices allocated to a virtual machine. The Hub in question is a USB hub which itself is plugged into one of the ports on the ...
Ryan Walmsley's user avatar
4 votes
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virtualbox to qemu but results in no bootable device qemu

I use vagrant to create my development vm. I exported the vmdk to vdi, and then convert the vdi to img. cd virtualbox_dir/test_vm VBoxManage clonehd test_vm.vmdk raw.vdi 0% ..... 100% qemu-img ...
Daniel Huger's user avatar
3 votes
2 answers
1k views

How can I recover the space in a qcow2 file after deleting snapshots, while retaining remaining snapshots?

I have a virtual machine that started out with 5 snapshots 1,2,3,4,5. I used qemu-img to delete snapshots 1,2,3. Snapshots 4 and 5 are still needed and were not deleted. How can I release the space ...
user73383's user avatar
3 votes
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Delayed start for Guests KVM/libvirt

Looking for any pointers anyone may have to introduce a delayed start for KVM guests i.e. 30 seconds between starting each virtual server rather than starting them all at once which thrashes the disks ...
Backtogeek's user avatar
3 votes
2 answers
768 views

Booting from firmware-based PCI RAID controller in SeaBIOS

I had a server running Windows 2003 that resided on a RAID5 array formed by Promise FastTrak SX4100, which I thought was hardware-based because of its dedicated processor and buffer memory and its ...
Anton Samsonov's user avatar
3 votes
0 answers
1k views

Qemu packer ssh failed connection reset by peer

I am trying to get packer to create a qemu/kvm image. I feel like it should be fairly straightforward but my build keeps failing on ssh. Here are the relevant files template.json: { "builders": [ { ...
C413's user avatar
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virt-install fully automated install

I'm looking into ways of installing/deploying a VM completely automated (no user interaction). So far I have tried QEMU and virt-install along with QEMU. The issue with qemu is that injecting ...
Harish's user avatar
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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 ...
Timothy Baldridge's user avatar
2 votes
0 answers
209 views

How to sucessfully import an .ova vm exported from ovirt/kvm (Red Hat OS)?

So, I was given an .ova file. This is exported from a server using a combination of KVM/QEMU and ovirt technologie - the server runs RedHat and I want to import this .ova file into vmware or ...
oolnux's user avatar
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2 votes
0 answers
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How to make a virtual disk image out of several parts?

During a process of moving to a virtualized infrastructure I encountered the following curious problem. We want to evaluate everything first. This involves creating a virtual images of all required ...
Nikita Kipriyanov's user avatar
2 votes
1 answer
2k views

Copy and paste from a QEMU VM with VNC graphics?

I run a headless server that uses qemu + kvm to run a few VMs, and I manage them with virsh + xml file definitions. Because this a remote / headless system, I set the graphics as VNC, and then with ...
Jason's user avatar
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qemu-kvm snapshot creations are extremely slow after a few first fast ones

Could anyone help me on this please? behavior I'm running several VMs with qemu-kvm and when creating some first few snapshots of a running VM, they are created super fast (roughly 10 seconds). ...
steffres's user avatar
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How to create Bridged connection for Qemu/KVM with Wifi?

I want to create a bridged connection in qemu/kvm. What I want to do is connect the wifi to a bridge (as a slave), then use this bridge to provide network access to the VM. Using nmtui, I deleted my ...
Matan L.'s user avatar
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kvm virtualization, slow io in windows guest (with virtio drivers) on ubuntu host and HP 360 Server with P440 RAID controller

Problem: Very slow IO in Windows Guest vs Host Hardware: HP 360 G9, 2 x 10 cores Xeon CPU, 128GB Ram, 4 x 4TB SAS HDD, Raid 10, P440 Controller (with 2GB cache and battery) Host: Ubuntu 20.04 Server, ...
Enovator's user avatar
2 votes
0 answers
2k views

Cloud Init with Flatcar Linux -- Configuration not applying when passing custom file?

I'm using Telmate's Terraform provider for Proxmox and trying to deploy Flatcar linux virtual machines using Cloud Init by passing files via cicustom. Based on their example, I have crafted the ...
TJ Zimmerman's user avatar
2 votes
0 answers
987 views

iotune qemu/KVM total_iops total_bytes limits

I have created some qemu/KVM virtual machines on SSDs. The host has ~6 SSDs. 1 is being used for the OS, and each of the other SSDs has two VM guests. I'm using iotune to limit the capabilities of ...
turbonerd's user avatar
2 votes
0 answers
947 views

Repeated loss of network connectivity to QEMU/KVM/virt-manager VM

I'm having frequent network connectivity failures under the QEMU/KVM/virt-manager stack on openSUSE Leap 15.1. I have a single VM running a software firewall, which is losing connectivity every few ...
BrokenLeap's user avatar
2 votes
0 answers
186 views

Making custom Kernel configuration changes with debian-installer in QEMU

I am installing Debian10 (armhf) on a virtual machine in QEMU, like this: Download this netboot/initrd.gz Download this netboot/vmlinuz Create an empty disk image with: qemu-img create -f qcow2 ...
George Robinson's user avatar
2 votes
1 answer
2k views

RHel 7 converted with qemu-img fails with dracut error at boot

I'll have to migrate several computers from Hyper-V to VmWare. I would like to use qemu-img because is command line and I could create an script. Conversion works fine for Windows but is not working ...
Uh Trog's user avatar
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2 votes
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QEMU-KVM bug: guest interface locks up a core with soft interrupts

Bug: I have a qemu-kvm on Ubuntu (host 14.04.5 LTS 3.13.0-95; cannot upgrade; , guest Ubuntu 18.04.03 LTS 4.15.0-65) Guest has two network interfaces, directly (VEPA) connected to two separate host ...
Alec Matusis's user avatar
2 votes
0 answers
653 views

How to fully emulate VM hardware?

How do I fully emulate, pass through, or spoof all the hardware for a virtual machine? I want to set up a few guest VMs in such a way that they do not have any special drivers or odd hardware info. ...
Max Power's user avatar
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XP KVM stuck at "Booting from Hard Disk"

Just to see if it could be done (and if so, move other physical XP machines to VM environments), I took the hard drive out of a decommissioned laptop, captured a WIM of it, and applied it to a QCOW2 ...
user38537's user avatar
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KVM guest gets into paused state shortly after being started

I have two very similar x86_64 machines running the same kernel (4.7.8), and the same version of libvirt. The only difference between the two machines is the amount of memory they have, machine A has ...
igalvez's user avatar
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2 votes
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Kernel panic when booting qemu virtual machine

I usually install template virtual machines on a dedicated server and then copy the disk to other production servers. It has worked for years and still works today in all cases but one. I have ...
Chebarbudo's user avatar
2 votes
0 answers
860 views

KVM/QEMU: cannot attach-device (disk) to a live domain

I'm trying to add a new disk to a running guest/domain (Win10) I succeed in using virsh attach-disk... --live and also using virsh attach-device.. --config But using: virsh attach-device SRV13 /tmp/...
MrCalvin's user avatar
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2 votes
0 answers
2k views

QEMU Network bridging for having a public IP

I simply want that my QEMU VMs have a public IP so I can run multiple servers in the same machine. I've read a lot of wikis, guides, tutorials, forum threads and anything related to this but still no ...
Megver83's user avatar
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2 votes
0 answers
1k views

How to configure QEMU DHCP and DNS for VMs?

I am trying to configure a QEMU setup with several VMs that talk to each other (e.g. a LDAP server on a VM that provides SSH authentication to other internal VMs). All these VMs are user mode and ...
Tiago Antao's user avatar
2 votes
0 answers
2k views

KVM/QUEMU guest slow disk performance

I'm really confused of QEMU/KVM behavior. I have a server - about 100GB RAM, 2 CPU - 6 core + HT, and three HDDs - one for root, and two for BTRFS-mirror for virtual machines (HGST HDN724030ALE640 if ...
slavka's user avatar
  • 21
2 votes
0 answers
3k views

Linux KVM QEMU Host with high CPU load

I have a machine running Ubuntu 16LTS with KVM/QEMU for a hypervisor. It has 1 guest running right now (A Ubuntu Server) that is using less than 1% of it's CPU and about 100MB of the 1000MB RAM ...
jtlindsey's user avatar
  • 323
2 votes
0 answers
2k views

Proxmox/KVM: Can not clone VM

I would like to create a clone of a KVM machine - yesterday I was able to create a clone of the same machine within some minutes. Now it takes hours and is still stuck an "0%": create full clone of ...
MyFault's user avatar
  • 913
2 votes
1 answer
550 views

vlan qemu: guest listening from other guests

I'm trying to simulate a little network of 3 machines using QEMU where a machine (deb1) is directly connected with the host and the other 2 machines (deb2, deb3): Host ...
DDK's user avatar
  • 23
2 votes
0 answers
521 views

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 ...
gucki's user avatar
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0 answers
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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 ...
rickatech's user avatar
  • 141
2 votes
0 answers
951 views

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 ...
stenio's user avatar
  • 163
2 votes
0 answers
2k views

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) ...
Matt's user avatar
  • 1,047
2 votes
0 answers
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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 ...
Steven Williamson's user avatar
2 votes
0 answers
599 views

Why is qemu issuing a DHCP discover after it receives a DHCP offer

I'm having some trouble seting up network on qemu. I'm trying the easy option (user). The qemu command I run is this: ./qemu-xilinx/arm-softmmu/qemu-system-arm \ -M xilinx-zynq-a9 -m 1024 -...
fakedrake's user avatar
  • 131
2 votes
1 answer
1k 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 /var/kvm/installation-disks/debian.img,...
nixnotwin's user avatar
  • 1,553
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
1 vote
1 answer
47 views

Set Maximum cpu qemu/libvirt almalinux

I want ask to increase supported CPU core on qemu kvm. When I creating new VM I see error like below error: internal error: QEMU unexpectedly closed the monitor (vm='ID'): qemu-system-x86_64: -accel ...
Hendra Setyawan's user avatar
1 vote
0 answers
179 views

KVM virt-install issue

I want to run arch linux as guest but after virt-install screen is stuck at console Escape character is ^] (Ctrl + ]).However VMs install by virt-manager are working fine and console is also working ...
Black_Bird's user avatar
1 vote
0 answers
203 views

Machine type issue when migrating KVM VMs with live snapshots from Debian to Ubuntu

I'm trying to migrate around 40 KVM VMs (containing a few hundred live snapshots mostly used for automated testing on Windows) from a Ubuntu 22 server to a Debian 11 server. The machine type of most ...
John Salazar's user avatar
1 vote
1 answer
461 views

Why qemu fails to start host only network on loopback when there's no other network on host?

Starting qemu-system-x86_64 with -nic user,ipv6=off,hostfwd=tcp::9022-:22 With only the lo interface (with 127.0.0.1 associated to it) present on the host, the vm will start, but any daemon trying to ...
gcb's user avatar
  • 72
1 vote
1 answer
605 views

How to use more then 2GB of ram when using running a nested BIOS VM using KVM

I have a Linux host running Debian 11 and on that host, I have a Ubuntu 22.04 VM. Inside that VM I want to run a Windows 10 VM using nested virtualization. The ubuntu VM is booted using EFI and nested ...
nezu's user avatar
  • 111
1 vote
0 answers
178 views

Backing encrypted drive

Creating a backing image for the master image that is encrypted using LUKS: qemu-img create -f qcow2 -b dev.qcow2 -F qcow2 -o encrypt.format=luks,encrypt.key-secret=dev --object secret,id=dev,data='...
Jonas's user avatar
  • 347
1 vote
0 answers
138 views

How do I force Virt-Manager to use the hosts' llvmpipe renderer so the guests get to use 3D acceleration?

I'm using virt-manager and set "3D Acceleration" as per what was recommended, but I'm getting this error: qemu_gl_create_compile_shader: compile vertex error 0:2(10): error: GLSL ES 3.00 is ...
X.LINK's user avatar
  • 111
1 vote
0 answers
465 views

QEMU boot with no progress for quite long after using the -enable-kvm option

I just wanna start a vm based on x86_64 via qemu, everything goes as expected(e.g. showing the console and login part) when I run the command below qemu-system-x86_64 \ -nographic \ -smp 4 \ -kernel ~/...
DESPERATE's user avatar

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