Adhi Priharmanto

Adhi Priharmanto

Victim of Cloud Deployment

KVM or Virsh Cheat Sheet

2 minute read

Just my note of Virsh Command

About Instance / Virtual Machine

Command About
virsh list List running Virtual Machine
virsh list --all List all Virtual Machines
virsh start <instance> Start Virtual Machine
virsh shutdown <instance> Shutdown Virtual Machine
virsh destroy <instance> Destroy Virtual Machine
virsh suspend <instance> Suspend Virtual Machine
virsh resume <instance> Resume Virtual Machine
virsh console <instance> Access Virtual Machine Console
to exit use this command :
Cntrl-]
virsh autostart <instance> Virtual Machine starts at boot
virsh autostart --disable <instance> Disable Virtual Machine starts at boot
virsh edit <instance> Virtual Machine Configuration
virsh save <instance> <filename> Save Virtual Machine to file
virsh restore $FILENAME Load Virtual machine from file
virt-clone \
--original [VM to Clone] \
--auto-clone \
--name [new name]		 Simple VM Cloning
virsh net-list List Running Network Configs
virsh net-list --all List All Network Configs
You can find network configs stored in /home/<user's>/network-configs/
virsh net-list [network name here] Edit Network Config
virsh net-create --file [full file path here] Create Temporary Network Config
virsh net-define --file [full file path here] Create Permanent Network Config
virsh net-start [network identifier] Start Network Config
net-autostart --network [network identifier] Enable Network Autostart
net-autostart --network [network identifier] --disable Disable Network Autostart
virsh snapshot-create <instance> Create Snapshot
virsh snapshot-create-as <instance> [name] Create Snapshot With Name
virsh snapshot-create-as [<instance> [name] [description] Create Snapshot With Name and Description
virsh snapshot-list <instance> List Snapshots
Snapshot-list defaults to being in alphabetical rather than chronological order. If you want to find out what your latest snapshots are, you may wish to add the optional --tree or --leaves parameters.
virsh snapshot-revert <instance> [Snapshot Name] Restore Snapshot
virsh snapshot-delete <instance> [Snapshot Name] Delete Snapshot
virsh blockresize <instance> --path vda --size 100G Online resizing instance
virsh dominfo show domain information
virsh vcpuinfo show domain vcpu information
virsh nodeinfo show node information
virsh quit Leave CLI

Network Example

Example Bridge Network Config File

<network>
  <name>examplebridge</name>
  <forward mode='route'/>
  <bridge name='kvmbr0' stp='on' delay='0'/>
  <ip address='192.168.1.1' netmask='255.255.255.0' />
</network>

Example Manual Network Config With Bridge

This example of network config ubuntu users in /etc/network/interfaces :

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto p17p1
iface p17p1 inet manual

auto kvmbr0
iface kvmbr0 inet static
    address 192.168.1.19
    netmask 255.255.255.0
    network 192.168.1.0
    broadcast 192.168.1.255
    gateway 192.168.1.254
    bridge_ports p17p1
    bridge_stp off
    bridge_fd 0
    bridge_maxwait 0

Configure VM To Use Manual Bridge

Edit the instance

virsh edit [guest identifier]

Find the following section

 <interface type='network'>
      <mac address='52:54:00:4d:3a:bd'/>
      <source network=''/>
      <model type='virtio'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>
    </interface>

Change into :

<interface type='bridge'>
        <mac address='52:54:00:4d:3a:bd'/>
        <source bridge='[bridge name here]'/>
        <model type='virtio'/>
        <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>
    </interface>

Power cycle the instance using shutdown and start command

virsh shutdown [guest identifier]
virsh start [guest identifier]

Resize Memory

Enter into instance configuration

virsh edit $VM_ID

Change the memory and currentMemory fields to be the size you want in KiB.

<domain type='kvm'>
...
  <memory unit='KiB'>52488</memory>
  <currentMemory unit='KiB'>52488</currentMemory>
...

Don’t Use “virsh memtune” Click here for reason

CPU Management

Discover CPU Scheduling Parameters

virsh schedinfo [guest ID or name]

Permanently Set CPU Shares For Live Running Instance

sudo virsh schedinfo [guest ID or name] \
--set cpu_shares=[0-262144] \
--live \
--current \
--config

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