virt-manager-QEMU-KVM-installation-guide

QEMU, KVM, virt-manager installation guide for archlinux

Install KVM packages

First step is installing all packages needed to run KVM:

sudo pacman -S qemu virt-manager virt-viewer dnsmasq vde2 bridge-utils openbsd-netcat

Also install ebtables and iptables packages:

#sudo pacman -S ebtables iptables

sudo pacman -S iptables-nft 

Install libguestfs

libguestfs is a set of tools used to access and modify virtual machine (VM) disk images. You can use this for:

• viewing and editing files inside guests
• scripting changes to VMs
• monitoring disk used/free statistics
• creating guests
• P2V
• V2V
• performing backup e.t.c

sudo pacman -S libguestfs
sudo systemctl enable libvirtd.service
sudo systemctl start libvirtd.service

also you might want to check if dnsmasq service is running

sudo systemctl enable dnsmasq.service
sudo systemctl start dnsmasq.service

Enable normal user account to use KVM

Since we want to use our standard Linux user account to manage KVM, let’s configure KVM to allow this.

Open the file /etc/libvirt/libvirtd.conf for editing.

sudo vim /etc/libvirt/libvirtd.conf

Set the UNIX domain socket group ownership to libvirt

unix_sock_group = "libvirt"

Set the UNIX socket permissions for the R/W socket

unix_sock_rw_perms = "0770"

Add your user account to libvirt group.

sudo usermod -a -G libvirt $(whoami)
newgrp libvirt

Restart libvirt daemon.

sudo systemctl restart libvirtd.service

Enable Nested Virtualization (Optional)

Nested Virtualization feature enables you to run Virtual Machines inside a VM. Enable Nested virtualization for kvm_intel by enabling kernel module as shown.

sudo modprobe -r kvm_intel
sudo modprobe kvm_intel nested=1

cat /sys/module/kvm_intel/parameters/nested

To make this configuration persistent,run:

echo "options kvm-intel nested=1" | sudo tee /etc/modprobe.d/kvm-intel.conf

Confirm that Nested Virtualization is set to Yes:

$ systool -m kvm_intel -v | grep nested
    nested              = "Y"
    nested_early_check  = "N"
$ cat /sys/module/kvm_intel/parameters/nested 
Y

Debug

Error starting domain: Requested operation is not valid: network 'default' is not active

sudo virsh net-list --all

Name      State      Autostart   Persistent
----------------------------------------------
 default   inactive   no          yes

sudo virsh net-start default