Questions tagged as ['kvm']

Questions about the Kernel-based Virtual Machine, an open source virtualization infrastructure to use the Linux kernel as a hypervisor.
Score: 0
Edoardo de Pietri Toneli avatar
sd flag

I have a bare metal server with RYZEN 9 5950X AMD and UBUNTU Ubuntu 18.04.6 LTS with VIRTUALIZOR KVM VIRTUALISATION and I am experiencing a crash problem very often.

Initially I thought it was a problem regarding the high CPU usage or a network crash due to too much bandwidth use by the different vpses.

Sometimes the server crashes for a few seconds and other times it goes completely offline until a ...

Score: 0
Anton Hinkel avatar
Windows 10 VM guest OS boots to a blue screen after restarting the host
us flag

I used Ubuntu 20.04 as host and create a Windows 10 VM (21H1) in KVM (via the GUI). In the VM I pass my graphics card (RTX2070) and the whole group via PCI passthrough, which works thanks to various guides.

After I installed updates/drivers in the VM, the graka is also recognized. I can also install programs or restart the VM without any problems, but as soon as I restart the host (with the VM sw ...

Score: 0
FAK avatar
Trying to install Windows 7 PE Lite on KVM Qemu but it goes straight to: "Press esc in 4 sec to skip startup.nsh or any other key to continue."
cn flag

I am trying to install a Windows VM on Qemu in ubuntu using Virt Manager, but it gives me the below screen:

enter image description here

And when I type exit, it will take me to the below screen:

enter image description here

Please suggest a fix.

Score: 1
user403329 avatar
A responsive live desktop 21.04 image produces a slow VM image
us flag

When I boot up a live desktop ISO in Virtual Machine Manager (kvm/qemu), the live system is super snappy and when I look at the "Resources" in the System monitor the 4 supplied cores are pretty much idle (RAM: 6GB, no problem).

Then I install the 21.04 desktop as "minimal". After the reboot the responsiveness experienced in the live ISO is not there anymore in the "true" VM. I can wait for hours, b ...

Score: 0
doeth avatar
PCI device listed in Device Manager with code 28
ca flag

I have this laptop and I'm trying to pass-through my MX130 to a Windows 10 VM. I'm using Ubuntu 20.04 (fully up-to-date). Packages installed (from the Ubuntu repositories): qemu-kvm libvirt-clients libvirt-daemon-system bridge-utils virt-manager ovmf


GRUB_CMDLINE_LINUX_DEFAULT="splash quiet intel_iommu=on kvm.ignore_msrs=1 vfio-pci.ids=10de:174d" 

lspci -nnk output:

.. ...
Score: 0
Ubuntu 20.04 server KVM Networking
ru flag

I am trying to find a solution to setup KVM with an internal NAT based bridge, I am using NetPlan for config

Essentially my server is a dedicated server from a provider so I do not have an internal network to play with. I know on the Windows platform with Hyper-V I can just create a VM switch and assign it an IP/mask, create a NAT for that IP/mask and boom! You have a gateway and subnet you can u ...

Score: 0
Legit4K avatar
Ubuntu 20.04.2 Temporary Failure in name resolution
es flag

About 2 weeks ago my VM became unreachable from the Internet - I can't access it via ssh, I can't access the files stored on it but I can ping it. I have KVM VNC Setup for it so I logged on and I tried to ping but it resulted in the Temporary failure in name resolution error. However, it is successfully able to ping IPs directly such as the DNS Server and any public IP.

I've bee ...

Score: 1
Jags avatar
Ubuntu MATE: How to enter and exit full screen view using key combination in virt-manager?
kp flag

Is there a key combination to enter and exit fullscreen view in virt-manager, while a virtual machine is running, and its window open?

Obviously I can enter or exit using mouse:

To enter: Click View > Fullscreen

To exit: Hover mouse at the top-center, and click Leave fullscreen icon.

I have tried key combinations from this AskUbuntu thread: How do I unmaximize full screen view in virt-manager?

Score: 0
jabroni avatar
Give static IP's to multiple QEMU Virtual Machines
cn flag

my networking knowledge on linux is pretty limited and I have been trying to assign static IP addresses to each of my VM's as they need to communicate with one another.

I have been reading some networking QEMU documentation regarding TUN/TAP interfaces, as well as configuring br0 with qemu-ifup and qemu-ifdown. However, I've just recovered from completely losing my wifi connection. So I have deci ...

Score: 0
Fazle Rabbi avatar
Guest can't access internet in KVM NAT
hu flag

Guests can't access internet in KVM NAT network. Guest can't ping host, the home router and other hosts on the lan but can't access website or ping DNS like or

Step to reproduce:

  1. On a fresh installation of Ubuntu 20.04 Desktop, I installed QEMU, KVM, bridge-utils and virt-manager with the following command: sudo apt-get install qemu-kvm libvirt-daemon-system libvirt-clients bridge-utils ...

Score: 0
VMs reset after suspend
us flag

Sometimes, when I close and open the notebook lid, my VMs are like this. It appears locked but actually what happened is that all the apps got closed and I to unlock the screen and reopen everything.

Both host and guest are ubuntu 20.04, and I'm using virt-manager.

enter image description here

Score: 0
Jun Shiozawa avatar
UEFI secure boot with QEMU KVM. But openssl x509 display Error
us flag

I want to do UEFI secure boot with QEMU KVM.

From the website below


Save to


~/mysecureboot/mymaster$ openssl x509 -in ${HOME}/Download/MicCorUEFCA2011_2011-06-27.crt -inform PEM -out myMicCorUEFCA2011_2011-06-27.der -outform DER

The following error is displayed.

unable to load certificate

140198688408896: er ...

Score: 0
Madeo avatar
df probably shows possibly wrong total
cn flag

I have recently spun up a new Ubuntu VM with Docker using KVM:

virt-install \
  --bridge=br0 \
  --name "${worker_name}" \
  --ram 4096 \
  --disk path=/var/lib/libvirt/images/"${worker_name}".qcow2,size=150 \
  --vcpus 2 \
  --cdrom /var/lib/libvirt/isos/ubuntu-20.04.2-live-server-amd64.iso \

As you can see I have set the size of the disk to 150GB, however when I run df -h --total ...

Score: 0
Clay avatar
VNC Connects to VM, not Host
uy flag

Running KVM on 20.04.2 LTS; I have two VMs running. When I use VNCViewer from a Windows box and connect to the IP of the KVM Host, I see a terminal window to one of the two VMs, NOT the host - any ideas appreciated.

Score: 0
MadPhysicist avatar
/dev/input/mouse0: is not an evdev device
br flag

I have been trying to set up a QEMU + KVM configuration to run a couple of VMs on Ubuntu as the host. I even have been able to passthrough a GPU successfully to the guests.

However, there seems to be an issue passing through input devices. No matter what I do or which guide I follow, I always get the following error in VM logs:

2021-07-17T11:22:42.556148Z qemu-system-x86_64: -object input-linux,id=mou ...
Score: 3
Maria Welborn avatar
VFIO nvidia code 43 despite hiding virtual machine
jp flag

I am using Ubuntu 21.04. I have a AMD Radeon RX550 and an Nvidia GTX 1050Ti

I am trying to set up VFIO passthrough for the nvidia card in a Windows VM. Windows reports error code 43 on the nvidia card in device manager after installing the nvidia drivers on the virtual machine and i'm stuck with 800x600 in the VM.

The primary card is the AMD (ie, the one that shows the BIOS post when turning on the  ...

Score: 0
Jags avatar
QEMU with KVM: Can not ping or SSH between host and guest machines
kp flag

Edit: Since macvtap is not working for communication between host and guest, I tried to used a bridge, but then there's no internet on the host and ping or ssh still doesn't work.

This is how I've created a bridge:

nmcli connection add type bridge ifname br0

Connection 'bridge-br0' (bf1406b0-4ea8-4338-9edc-0f58fd019bec) successfully added.

nmcli con add type ethernet con-name br-slave- ...
Score: 0
Insideup avatar
How to recover host disk space? Lost with KVM running out of memory while adding and removing virtual disks wtih Virtual Machine Manager
fr flag

While using KVM and the Virtual Machine Manager, I discovered I was running out of disk space, while doing the following:

  1. Virtual Machine Manager, Details view, select VirtIO Disk 1, right click and select Add Hardware, enter a size.
  2. Run the VM and test.
  3. Shutdown the VM.
  4. Virtual Machine Manager, Details view, select VirtIO Disk 2, right click and select Remove Hardware.
  5. Virtual Machine Manager, Details v ...
Score: 0
qhx avatar
Ubuntu 20.04 KSM not working
kw flag

I want to use KSM in Ubuntu 20.04 to achieve memory sharing between to qemu VMs. And I installed ksmtuned as follows:

$ sudo apt install ksmtuned

But I found KSM not working, and systemctl show as follows:

$ systemctl status ksm.service
● ksm.service - Kernel Samepage Merging
     Loaded: loaded (/lib/systemd/system/ksm.service; enabled; vendor preset: enabled)
     Active: active (exited) since Mo ...
Score: 0
mitchelangelo avatar
Exit read-only file system after system crash and hard reset (20.04.2 Server, VM)
in flag

Yesterday my system crashed forcing me to do a hard reset on my host machine whilst running 2 virtual machines. The first machine survived and the second has been put into a read only mode. After logging in to the VM I am presented with the following messages.

Unable to setup logging. [Errno 30] Read-only file system: '/var/log/landscape/sysinfo.log' run-parts: /etc/update-mot.d/50-landscape-sysinfo  ...

Score: 0
VMs (virt-manager) are slow on 21.04 but not 20.04
us flag

On Ubuntu 21.04, VMs run slow. I used Ubuntu 21.04 on both host and guest and the VMs were very slow, even on moving the windows with the mouse. I had to go back to Ubuntu 20.04 where they work fine.

I use virt-manager by the way, installed through sudo apt-get install -y virt-manager, I did not change any VM configurations, I simply created a new one and installed.

What could possibly be happeni ...

Score: 0
AndersonReloaded avatar
KVM networking: OSPF between Vyos VMs running across different hosts
in flag

Unable to establish OSPF neighbourhood between Vyos-1.3 VMs running across different hosts. On each host, one interface of Vyos VM's are connected to host physical interface using 'macvtap'. Running 'tcpdump' on host's physical interface shows OSPF packets being sent and received to multicast address. However, the Vyos VMs doesn't seem to form neighbourhood.

Suggestions on how to make it through and d ...

Score: 0
mike243 avatar
ABLEWE KVM and 2 Pi4s, both work, 20.04LTS. Leave over night. Select the pi4 not shown. Display says no sig, type enter, display says out of range?
in flag

The hdmi configuration has evidently been changed by ubuntu, thinking the monitor changed. How to prevent this?

Score: 0
Omer Menahse avatar
KVM - PCI Passthrough
in flag

Im trying to pass a PCI device to a KVM Virtual Machine, The VM recognize the PCI device, I can see it on lscpi But im getting these errors: 1. "pcilib: sysfs_write: write failed: File too large". 2. failed to map bar 0 to 0x...

Host: Linux 5.4.0-42-generic #46~18.04.1-Ubuntu x86_64 Virtual Machine Manager: 1.5.1 Virtual Machine OS: 4.15.0-147-generic #151-ubuntu x86_64

Score: 1
Anurag Pathak avatar
How to use microphone in KVM, virt-manager based Virtual Machine?
li flag

I am using Ubuntu 20.04.2 (64-bit) as host and Q4OS(32-bit) as guest. I have added camera from USB host devices and hence it works now on using google meet in virtual machine.

But I am still unable to use mic there and meet says that my mic is not working. What can I do? (Please note that I haven't added mic from usb host device as I can't find it there).

Score: 2
How to use OpenGL/3D acceleration in virt-manager with ubuntu?
us flag

Currently on Ubuntu 20.04 both as host and guest, I followed and activated 3D acceleration on video, and OpenGL on dsplay, but on VM launch I get

SPICE GL support is local only for now and incompatible with -spice port/tls-port

How can I make it work?


I disabled Listen Type to None

like thisenter image description here

but I get a very glitchy image:

enter image description here

Score: 0
How to redirect an USB 3.0 device to VM in virt-manager?
us flag

usb 3.0 devices never worked on virt-manager for me. I'm running Ubuntu 20.04 on both host and guest, and only 2.0 redirection works. When I do 3.0, it simply does not appear on the guest on lsusb neither on disks (for a flash drive for example)

I'm using the "redirect usb device" option, and the virt-manager is 2.2.1

Score: 0
QEMU freezes when booting with USB drive passthrough
au flag


I'm trying to read the contents of a USB 3 external hard drive. It's got a GPT partition table, with almost all space allocated to a single Core Storage partition, which contains a single HFS+ volume of interest.

I haven't been able to natively mount it on linux using libfvde; the resultant block device isn't recognized by either hfsfuse or hfsprogs as being a valid HFS+ volume. I know the volume  ...

Score: 0
Why am I logging in as "kvm" instead of my normal username?
no flag

One day I booted my computer and logged in and my desktop was empty. I was now in /home/kvm/Desktop. I never created this user. All my stuff is still under home/ben, so no data has been lost. kvm however does not have sudo privileges, and I am not sure how to log in as 'ben.'

The only thing I can think of is my cat typed something while I was away.

How do I begin to address this problem?

Score: 0
kevin calinog avatar
I tried launching Sosumi and got this error message
cn flag

I get the error message "Could not access KVM kernel module: No such file or directory qemu-system-x84_64: failed to initialize KVM: No such file or directory"

I have a Intel(R) Core(TM) i7-8700K CPU @ 3.70GHz 3.70 GHz and on my task manager performance tab, under CPU it states that I have virtulization enabled.

What must I do to enable virtulization on Ubuntu?