KVM Commands
virsh dialogue terminal
$ virsh --connect qemu:///system virsh # list --all
virsh commands
| Command | Description |
|---|---|
| virsh list ← active guest only virsh list –all virsh list –autostart virsh list –all –autostart virsh list –all –no-autostart virsh list –inactive ← inactive guest only | check virtual server status |
| virsh dominfo GUEST | checking guest information(CPU, Memory, Auto start) |
| virsh console GUEST | For logout with ‘CTRL+]’ |
| virsh vncdisplay GUEST | :0 is TCP 5900 :1 is TCP 5901 |
| virsh start GUEST | |
| virsh autostart GUEST virsh autostart –disable GUEST | guest start with os boot Check ls -lh /etc/libvirt/qemu/autostart/ |
| virsh shutdown GUEST | |
| virsh destroy GUEST | Force terminate OS |
| virsh edit GUEST | edit xml file for cpu numbers, memory size. The place of xml file is /etc/libvirt/qemu/GUEST.xml. |
| virsh dumpxml GUEST | less virsh dumpxml GUEST | grep mac virsh dumpxml GUEST | grep graphics | grep port | |
| virsh define /etc/libvirt/qemu/SERVER.xml virsh define xxxxx.xml | registration new virtual machine |
| virsh create /etc/libvirt/qemu/SERVER.xml virsh create xxxxx.xml | registration new virtual machine and start |
| virsh undefine SERVER | virsh undefine will delete XML configuration file.If you need the XML Configuration file, please backup XML file. And Image file isn’t delete. Check the place of disk file before undefine. And delete image file. virsh dumpxml Guest |grep file |
| virt-clone –original ORG –name NEW –file /etc/libvirt/qemu/ORG/ORG.img |
Installing KVM in Host OS
yum install kvm yum install virt-manager libvirt libvirt-python python-virtinst or yum groupinstall Virtualization "Virtualization Client" "Virtualization Platform" "Virtualization Tools"
chkconfig libvirtd on
KVM Networking
Checking KVM Network
# brctl show
Creating Bridge Interface
Creating Bridge Interface with brX
| brX Basic | /etc/sysconfig/network-scripts/ifcfg-eth0 /etc/sysconfig/network-scripts/ifcfg-br0 |
| brX bonding | /etc/modprobe.d/bonding.conf /etc/sysconfig/network-scripts/ifcfg-bond0 /etc/sysconfig/network-scripts/ifcfg-eth0 /etc/sysconfig/network-scripts/ifcfg-eth1 /etc/sysconfig/network-scripts/ifcfg-br0 |
| brX VLAN | /etc/sysconfig/network /etc/sysconfig/network-scripts/ifcfg-bond0 /etc/sysconfig/network-scripts/ifcfg-bond0.10 /etc/sysconfig/network-scripts/ifcfg-bond0.20 /etc/sysconfig/network-scripts/ifcfg-br10 /etc/sysconfig/network-scripts/ifcfg-br20 |
Creating Bridge Interface with virbrX
This bridge is use iptables’s NAT function.
How to delete virbr0 of NAT.
# brctl show # ifconfig virbr0 # virsh net-destroy default # brctl show # virsh net-list --all # virsh net-autostart default --disable # virsh net-list --all
KVM Guest OS
File Composition
| Command | Description |
|---|---|
| configuration file | /etc/libvirt/qemu/HOST.xml |
| disk file | /var/lib/libvirt/images/HOST.img |
Log
| /var/log/libvirt/libvirtd.log | |
| /var/log/libvirt/qemu/test-server.log |
Snapshot
- If you want to use snapshot, you must use a qcow2 file format.
| Command | Description |
|---|---|
| create snapshot | virsh snapshot-create-as [Guest_Name] [Snapshot_Name] [Description] |
| recovery snapshot | virsh snapshot-revert [Guest_Name] [Snapshot_Name] |
| list snapshot | virsh snapshot-list [Guset_Name] virsh snapshot-list [Guset_Name] –tree |
| delete snapshot | virsh snapshot-delete [Guset_Name] [Snapshot_Name] |
LiveMigration
virsh migrate --live centos7 qemu+ssh://xx.xx.xx.xx/system
Tips
KVM Image Mount
# kpartx -av disk.img # mount /dev/mapper/loop0p1 /mnt <- loop0p1 or loop0p2 or loop0p3 etc # cd /mnt/ # ls -al # umount /mnt # kpartx -dv disk.img
source: https://cmdref.net/middleware/virtualization/kvm/index.html