KVM

Links

virsh -c 'qemu+ssh://[email protected]/system?socket=/var/run/libvirt/libvirt-sock' net-list --all

virt-host-validate
/usr/libexec/qemu-kvm -machine help

Install libvirt and kvm

Install libvirt on Centos 8

yum groupinstall "Virtualization Host"

systemctl start libvirtd

systemctl enable libvirtd

virsh version

Allow QEMU/KVM Commands Without Root:

usermod -aG libvirt $(whoami)

yum install virt-install

Install libvirt on Ubuntu

apt-get install cpu-checker qemu-kvm libvirt-daemon-system libvirt-clients bridge-utils

Add user to group libvirt and kvm

$ sudo adduser `id -un` libvirt
Adding user '<username>' to group 'libvirt' ...
$ sudo adduser `id -un` kvm
Adding user '<username>' to group 'kvm' ...

Verify Installation

$ virsh list --all
 Id Name                 State
----------------------------------
$

Install libvirt on Alpine

Getting Started: Alpine Linux

Alpine KVM

Alpine Linux as a KVM host

apk add libvirt-daemon qemu-img qemu-system-x86_64 polkit
rc-update add libvirtd
mkdir -p /etc/polkit-1/localauthority/50-local.d

Create file /etc/polkit-1/localauthority/50-local.d/50-libvirt-ssh-remote-access-policy.pkla:

[Remote libvirt SSH access]
 Identity=unix-group:libvirt
 Action=org.libvirt.unix.manage
 ResultAny=yes
 ResultInactive=yes
 ResultActive=yes

Optional addgroup libvirt

For client:

apk add libvirt libvirt-client py3-libvirt

apk add qemu-img qemu-system-x86_64

How view output from vm

How to Setup QEMU Output to Console and Automate Using Shell Script

-nographic does the same as "-serial stdio" and also hides a QEMU's graphical window.

-serial stdio redirects the virtual serial port to the host's terminal input/output. You will see a welcome string after a successful boot.

-serial stdio

-monitor none

Networks

Network Suse KVM

-netdev user,id=net0,hostfwd=tcp::10022-:22
-device e1000,netdev=net0

# create virtual network
virsh net-create VNET_DEFINITION.xml
# To define a new virtual network without activating it
virsh net-define VNET_DEFINITION.xml

# to view all network
virsh net-list --all

virsh domifaddr nated_sles12sp3 --interface vnet0 --source lease
virsh net-info vnet_routed
virsh net-start vnet_isolated
virsh net-destroy vnet_isolated
virsh net-undefine vnet_isolated

NAT-BASED Network

<network>
<name>vnet_nated</name>
<bridge name="virbr1"/>
 <forward mode="nat"/>
 <ip address="192.168.122.1" netmask="255.255.255.0">
  <dhcp>
   <range start="192.168.122.2" end="192.168.122.254"/>
   <host mac="52:54:00:c7:92:da" name="host1.testing.com" \
    ip="192.168.1.23.101"/>
   <host mac="52:54:00:c7:92:db" name="host2.testing.com" \
    ip="192.168.1.23.102"/>
   <host mac="52:54:00:c7:92:dc" name="host3.testing.com" \
    ip="192.168.1.23.103"/>
  </dhcp>
 </ip>
</network>

Routed Network

<network>
 <name>vnet_routed</name>
 <bridge name="virbr1"/>
 <forward mode="route" dev="eth1"/>
 <ip address="192.168.122.1" netmask="255.255.255.0">
  <dhcp>
   <range start="192.168.122.2" end="192.168.122.254"/>
  </dhcp>
 </ip>
</network>

Isolated Network

<network>
 <name>vnet_isolated</name>
 <bridge name="virbr3"/>
 <ip address="192.168.152.1" netmask="255.255.255.0">
  <dhcp>
   <range start="192.168.152.2" end="192.168.152.254"/>
  </dhcp>
 </ip>
 </network>

Using existing Bridge

ip link add name VIRBR_TEST type bridge
bridge vlan
ip link set virbr_test up
ip link set eth1 master virbr_test
# optional enable STP
bridge link set dev virbr_test cost 4

<network>
        <name>host-bridge</name>
        <forward mode="bridge"/>
        <bridge name="br0"/>
</network>

Command line

MacOS Connect to KVM Client Desktop

homebrew-virt-manager

Configuring Virtual Machines with virsh

virsh -c 'qemu+ssh://[email protected]/system'
virsh -c 'qemu+ssh://[email protected]/system?socket=/var/run/libvirt/libvirt-sock'
virsh -c 'qemu+ssh://[email protected]/system?socket=/var/run/libvirt/libvirt-sock' net-list --all
virt-manager -c 'qemu+ssh://[email protected]/system?socket=/var/run/libvirt/libvirt-sock'

Connect to Vmware

virsh -c esx://192.168.180.45?no_verify=1

virsh list

virsh list --all

virsh dumpxml instance-00000fc5

virsh dommemstat instance-0000000d

virsh dominfo instance-00000032

virsh vcpuinfo instance-0000000d

virsh vcpucount instance-0000000d

How read file img with partition

fdisk -l config.img

mount -o ro,loop,offset=32256 config.img /mnt/

Можно с использованием losetup -f -P hdd.img

How To Mount ISOs And Other Image File Types In Linux?

Convert format disks

qemu-img convert -f raw -O qcow2 image.img image.qcow2
qemu-img convert -f vmdk -O raw image.vmdk image.img
qemu-img convert -f vmdk -O qcow2 image.vmdk image.qcow2

disk utilities

ioping and pgbench

How To Install IOPing on CentOS 7

Тестирование IOPS дисков в Linux

How to Check Linux VPS/Server Disk I/O Speed via this Simple Commands

dd if=/dev/zero of=test bs=64k count=16k conv=fdatasync && rm -rf test

dnf install epel-release
dnf install fio

fio --randrepeat=1 --ioengine=libaio --direct=1 --gtod_reduce=1 --name=fiotest --filename=testfio --bs=4k --iodepth=64 --size=8G --readwrite=randrw --rwmixread=75

fio --randrepeat=1 --ioengine=libaio --direct=1 --gtod_reduce=1 --name=fiotest --filename=testfio --bs=4k --iodepth=64 --size=8G --readwrite=randread

ioping и pgbench

yum -y install epel-release
yum -y install ioping

ioping -s4k -S1G -L -A -D -i0 -q -c100000 /dev/sda

ioping -s4k -S10G -A -D -i0 -q -c100000 /dev/sda

Python libvirt

GITHUB examples libvirt-python

qemu-system-x86_64 -name debian -vnc 146.20.141.254:0 -cpu Nehalem -m 1024 -enable-kvm -drive format=raw,index=2,file=debian.img -daemonize

qemu-system-x86_64 -vnc 146.20.141.254:0 -m 1024 -hda CentOS-7-x86_64-GenericCloud.qcow2 -daemonize

/usr/libexec/qemu-kvm --cpu help

pgrep -lfa qemu

virsh

Connect

export VIRSH_DEFAULT_CONNECT_URI='qemu+ssh://[email protected]/system?socket=/var/run/libvirt/libvirt-sock'

Install

virt-install --virt-type=kvm --name MasteringKVM01 --vcpus 2 --ram 4096 \
 --os-variant=centos8 \
 --cdrom=/var/lib/libvirt/images/CentOS-8.2.2004-x86_64-minimal.iso  \
 --network=default \
 --graphics=vnc \
 --disk size=16

virt-viewer -c 'qemu+ssh://[email protected]/system?socket=/var/run/libvirt/libvirt-sock'

virt-install --virt-type=kvm --name=MasteringKVM02 --ram=4096 --vcpus=4 \
 --os-variant=rhel8.0 \
 --location=/var/lib/libvirt/images/ CentOS-8-x86_64-1905-dvd1.iso \
 --network=default \
 --graphics vnc \
 --disk size=16 \
 -x "ks=http://10.10.48.1/ks.cfg"

Snapshot

virsh snapshot-create-as --domain admin_server1 --name "Snapshot 1"2 \
	--description "First snapshot"

virsh snapshot-list --domain admin_server
virsh snapshot-current --domain admin_server
virsh snapshot-info --domain admin_server \
	-name  "Basic installation incl. SMT for CLOUD4"
	
virsh snapshot-delete --domain admin_server --snapshotname "Snapshot 2"

virsh snapshot-revert --domain admin_server --snapshotname "Snapshot 1"
virsh snapshot-revert --domain admin_server --current

Virsh console

Linux kvm exit from a virsh console command

Virsh rename domain

virsh domrename currentname  newname

Virsh change domain boot disk

virsh  edit domain

# Scroll down until <devices> section and modify values for the line below:
<source file=''/>

# Example
<source file='/var/lib/libvirt/images/apacheserver01.qcow2'/>

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Last updated 1 year ago