back Managing VMs on libvirt
comp
publication: Janeiro 30 2021 19:29
last update: Janeiro 30 2021 19:29
install libvirt
# apt-get install libvirt-daemon-system qemu-system
if you wish a GUI manager:
# apt-get install virt-manager
if you wish a CLI manager:
# apt-get install libvirt-clients virtinst
add user to libvirt group
If you wish to use libvirt as a regular user, you need to add the user to libvirt group:
# usermod -aG libvirt USER
you need to relog after this.
managing vms
The commands below need libvirt-clients package:
-
list all vms:
# virsh list --all -
start vm:
# virsh start VM -
stop vm:
# virsh shutdown VM -
force stop vm:
# virsh destroy VM -
delete vm:
# virsh undefine VM
# virsh undefine --remove-all-storage VM -
list all networks:
# virsh net-list --all -
start a bridge network:
# virsh net-start NETWORK -
stop a bridge network:
# virsh net-destroy NETWORK -
list ip of vms connected to the default bridge network:
# virsh net-dhcp-leases default
installing a guest
# virt-install --virt-type=kvm --name=debian10 --ram=2048 --vcpus=2 \
--os-variant=debian10 --hvm --cdrom=/var/lib/libvirt/boot/debian-10.9.0-amd64-netinst.iso \
--graphics vnc --disk path=/var/lib/libvirt/images/debian10.qcow2,size=20,bus=virtio,format=qcow2
Starting install...
Allocating 'debian10.qcow2' | 20 GB 00:00:03
Domain installation still in progress. Waiting for installation to complete.
Get VNC port:
# virsh dumpxml debian10 | grep vnc
<graphics type='vnc' port='5900' autoport='yes' listen='127.0.0.1'>
SSH port forwarding to get access to VNC:
# ssh -L 5900:127.0.0.1:5900 user@vm-host.example.com
and connect to 127.0.0.1:5900 on your VNC client.
clone and reset vm
Install libguestfs-tools:
# apt-get install libguestfs-tools
Clone and configure the cloned VM:
# virt-clone --original ORIGINAL_VM --name NEW_VM --auto-clone
--auto-clone uses the same vm settings from ORIGINAL_VM on NEW_VM.
# virt-sysprep -d NEW_VM --root-password password:NEW_PASSWORD \
--hostname HOSTNAME --ssh-inject USER:file:PATH_TO_SSH_PUB_KEY \
--firstboot-command "dpkg-reconfigure openssh-server" \
--firstboot init-config.sh
or
# virt-sysprep -d NEW_VM --password USER:password:NEW_PASSWORD \
--hostname HOSTNAME --ssh-inject USER:file:PATH_TO_SSH_PUB_KEY \
--firstboot-command "dpkg-reconfigure openssh-server" \
--firstboot init-config.sh
--root-password defines root password
--password defines USER password
--hostname defines vm hostname
--ssh-inject copy ssh public key to USER ~/.ssh/authorized_keys file
--firstboot-command executes a command on the first boot (reconfiguring openssh is necessary as virt-sysprep deletes ssh keys)
--firstboot init-config.sh runs the script init-config.sh on first boot
tuning
Use virsh edit VM and the lines below after the line <vcpu ...
<cputune>
<vcpupin vcpu='0' cpuset='0'/>
<vcpupin vcpu='1' cpuset='4'/>
<vcpupin vcpu='2' cpuset='1'/>
<vcpupin vcpu='3' cpuset='5'/>
</cputune>
source:
https://wiki.debian.org/KVM
https://www.cyberciti.biz/faq/reset-a-kvm-clone-virtual-machines-with-virt-sysprep-on-linux/