63 votes

Windows 10 in KVM: change boot disk to Virtio

All the answers are correct but you may need to perform few additional steps after you have installed virtio drivers. Here are the steps I followed: Configure boot disk as SATA and start the VM. ...
llegolas's user avatar
  • 639
54 votes

libvirt: "Failed to initialize a valid firewall backend"

Installing ebtables and dnsmasq seems to fix the problem. Don't forget to restart the libvirtd service. The commands: sudo pacman -Syu ebtables dnsmasq sudo systemctl restart libvirtd NOTE: do not ...
AliReza Mosajjal's user avatar
47 votes

Windows 10 in KVM: change boot disk to Virtio

A fairly simple answer is provided - and may work in many cases, along with hints at other options. If (like me) you're not able to switch to IDE and forced to use VirtIO, then the following ...
JPvRiel's user avatar
  • 1,571
30 votes

How to increase the visualized screen resolution on QEMU / KVM?

-vga virtio Using this option allows me to go all the way up to 4096 x 2160. Of course, this is useless since my display only goes up to 1080p, so I set 1080p. Then you can toggle fullscreen with Ctrl ...
Ciro Santilli OurBigBook.com's user avatar
25 votes
Accepted

Hiding Virtual machine status from guest operating system

There are two things you need to do to hide the hypervisor from the guest OS: Hide the hypervisor CPU feature flag. Hide the hypervisor CPUID leaves. Neither of these can be done entirely in virt-...
Michael Hampton's user avatar
23 votes
Accepted

What is the difference and relationship between kvm, virt-manager, qemu and libvirt?

KVM is able to create VMs independently without any support of ther Hypervisors such as QEMU. Yes and no; it can create VMs but cannot provide hardware other than CPU & RAM. Why virt-manager ...
u1686_grawity's user avatar
18 votes

How to increase the visualized screen resolution on QEMU / KVM?

2021 Solution for virt-manager users Steps Open terminal virt-manager Open VM settings Go to "Video" tab Change to "Virtio" Run / restart VM Open settings in guest OS (eg I run ...
user3728501's user avatar
  • 2,624
18 votes

No Auto Resize with SPICE and virt-manager

The gnome desktop, mutter, has some hotplug code that deals with the resize. If you have any other desktop like xfce4 or KDE or a bare .xinitrc file running compiz like I do, you are pretty stuck, but ...
gsker's user avatar
  • 191
17 votes
Accepted

Do I need both the QEMU Agent and SPICE Agent installed in Windows 10 guest?

The QEMU Guest Agent (qemu-ga) and the SPICE agent are both needed for different purposes. "QEMU Guest Agent" is one specific component of the 'virtio-win' set of drivers offered by RedHat. ...
Marc.2377's user avatar
  • 1,527
16 votes

libvirt/9p/kvm mount in fstab fails to mount at boot time

In 2020, a better way to delay the mount until the time when we have access to the 9p modules from /lib/modules is to add _netdev as a mount parameter: /data /data 9p trans=virtio,rw,_netdev 0 ...
Mikael Gueck's user avatar
13 votes

Windows 10 in KVM: change boot disk to Virtio

The steps to follow in general are : Install the VirtIO drivers in the VM Set the system disk of the VM to use VirtIO If the VM does not boot, execute Startup Repair or even Repair Install The ...
harrymc's user avatar
  • 475k
11 votes

How do I prevent virt-manager from asking for the root password?

I found that simply adding my user to libvirt and kvm groups stopped the prompts. sudo usermod -a -G libvirt $(whoami) sudo usermod -a -G kvm $(whoami) whoami outputs your username that way it will ...
velis's user avatar
  • 555
11 votes
Accepted

How to configure macvtap to let it pass multicast packet correctly?

libvirt's macvlan has gained support for multicast. Unfortunately it is disabled by the default setting trustGuestRxFilters="no", and the documentation is not explicit that this breaks multicast. As ...
sourcejedi's user avatar
  • 3,252
11 votes

Windows 10 in KVM: change boot disk to Virtio

the answer from harrymc works fine for me. the following steps I followed: Install the virtio driver in windows Add a additional "dummy" virtio disk. Reboot and check if the "dummy" works. If Step 2 ...
sdhd's user avatar
  • 111
11 votes

libvirt: "Failed to initialize a valid firewall backend"

This is the error that comes up if libvirtd was started without ebtables and/or dnsmasq installed. If you've got them installed and you're still having this issue, you probably need to restart the ...
Stuart P. Bentley's user avatar
9 votes

How to exit a "virsh console" connection?

Danish keyboard: Ctrl+Shift+^¨~ English keyboard: Ctrl+Shift+5 Ctrl+Shift+] French keyboard: Ctrl+Shift+5 Ctrl+Shift+$€* (OS X) German keyboard: Ctrl+Shift+5 Strg+Shift+5 ctrl+alt+6 (Mac) ...
8 votes

How to configure macvtap to let it pass multicast packet correctly?

The answer by sourcejedi contains the solution, but maybe not explicitly enough. Using "virsh edit", set the trustGuestRxFilters attribute on the network device: <interface type='direct' ...
uncleremus's user avatar
8 votes

vagrant fails to create box with libvirt

I got this Error while connecting to libvirt error but it was because I was running vagrant up without specifying the provider. In my case I needed $ vagrant up --provider virtualbox
icc97's user avatar
  • 595
8 votes

Two mouse cursors when using virt-manager

As described here this can sometimes happen when creating a fully virtualized guest. The page I linked to also suggests a workaround: you can add a "Graphics Tablet" device to your VM. To do this: ...
Андрей Беньковский's user avatar
8 votes

No Auto Resize with SPICE and virt-manager

I'm using Debian 10 and icewm as guest VM. When spice-vdagent is running I can manually adjust the screen size with xrandr --output Virtual-1 --auto A change in the display size can also be observed ...
Joe H.'s user avatar
  • 81
7 votes

Windows 10 in KVM: change boot disk to Virtio

It is unfortunately possible to have driver perfectly installed and STILL get "inaccessible boot Device." The reason is a bit shocking (I find): a Win 10 installation "remembers" the drivers that were ...
Scott Petrack's user avatar
7 votes
Accepted

Two mouse cursors when using virt-manager

This is an issue with KVM, not just virt-manager. It's possible to fix on the command-line for users not using virt-manager: Shut down your VM Enter the following on the host command-line: GUEST=...
mtlynch's user avatar
  • 501
6 votes

Where can I config service startup options in Ubuntu?

First find your config you want to change using the following command: systemctl list-unit-files Then change the specific config using the following command: sudo systemctl edit --full rocketchat....
KayV's user avatar
  • 161
6 votes
Accepted

Configuring KVM inside Ubuntu Hyper-V client

The article Running KVM Nested in Microsoft Hyper-V reports this procedure : Download this PowerShell script from Github (written by Microsoft) Copy the script to your desktop Open up an elevated ...
harrymc's user avatar
  • 475k
6 votes

How to boot a UEFI image from a KVM virtual machine without `virt-manager`? (e.g. Home Assistant on OpenMediaVault/Cockpit)

Disclaimer: I am not really familiar with UEFI, don't even know exactly what it does, so if this answer can be improved, please comment or edit accordingly. This is what worked for me: apt-get install ...
Christoph's user avatar
  • 1,933
5 votes

Using virt-install to mount multiple cdrom drives/images

Because you can't use --cdrom twice, you can you --disk ...,device=cdrom,bus=ide instead. It works for me: virt-install \ --virt-type=kvm \ --name=win10 \ --ram=4096 \ --cpu=host \ --vcpus=2 \ --os-...
Toanalien's user avatar
  • 151
5 votes

Windows 10 in KVM: change boot disk to Virtio

Wow, lot's of shenanigans. Why not just using Arch Wiki's QEMU approach? First have your virtio-win-0.1-81.iso ready. Download from RedHat. 1 - Create a fake (dummy) disk with $ qemu-img create -f ...
Adriano_pinaffo's user avatar
5 votes
Accepted

ZFS vs raw disk for storing virtual machines: trade-offs

ZFS can be (much) faster or safer in the following situations: If you are contemplating using some other software RAID or bios RAID solution (e.g., not a dedicated piece of hardware with a relatively ...
allquixotic's user avatar
  • 34.5k
5 votes
Accepted

How to(Libvirt) attach floppy image device to guest VM?

You need device=floppy, dev=fda and bus=fdc, e.g. <disk type='file' device='floppy'> <source file='/var/lib/libvirt/images/floppy.vfd'/> <target dev='fda' bus='fdc'/> </disk&...
DanielB's user avatar
  • 311
5 votes

KVM GPU passthrough of nVidia dGPU on laptop with hybrid graphics without proprietary drivers on host

Verify if your nVidia graphics card is MUXed or MUXless. If you can find BIOS option to choose "integrated graphics" and "PCI graphics" (Whatever name), then it is MUXed. Else is MUXless. If it is ...
user3336503's user avatar

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