Are you trying to manage KVM guest virtual machines using virsh commands?
This guide is for you.
virsh is a command line interface tool for managing guests and the hypervisor. The virsh tool is built on the libvirt management API and operates as an alternative to the xm command and the graphical guest Manager ( virt-manager ).
Virsh interacts with Libvirt which is a library aimed at providing a long-term stable API. It currently supports Xen, QEMU, KVM, LXC, OpenVZ, VirtualBox, and VMware ESX.
It can be used to create, pause, restart, and shutdown domains. In addition, it can be used to list current domains available in our Virtualization hypervisor platform.
Here at Ibmi Media, as part of our Server Management Services, we regularly help our Customers to manage KVM guest virtual machines by means of virsh commands.
In this context, we shall look into how to use Virsh commands.
The basic structure of most virsh usage is given below:
virsh [OPTION]... <command> <domain> [ARG]...
To display the host node information and the machines that support the virtualization process, we can use the following command:
$ sudo virsh nodeinfo
To list both inactive and active domains, we can use the following command:
$ sudo virsh list --all
For listing only active domains we can use the following command:
$ sudo virsh list
For starting a VM we can use the following command by replacing 'domain_name' with the required domain name:
$ sudo virsh start domain_name
$ sudo virsh list
To set a VM to start automatically on system startup, we can use the following command:
$ sudo virsh autostart domain_name
$ sudo virsh dominfo domain_name
To disable autostart feature for a VM, we can use the following command:
$ virsh autostart --disable domain_name
$ virsh dominfo domain_name
To shut down a running VM gracefully, we can use the following command:
$ sudo virsh shutdown domain_name
$ sudo virsh list
To perform a forceful shutdown of the active domain we can use the following command:
$ sudo virsh destroy domain_name
To shut down all running domains, we can use the following command:
$ for i in `sudo virsh list | grep running | awk '{print $2}'` do
sudo virsh shutdown $i
done
To restart a VM we can use the following command:
$ sudo virsh reboot domain_name
To cleanly remove a VM including its storage columns, we can use the following commands:
$ sudo virsh destroy domain_name 2> /dev/null
$ sudo virsh undefine domain_name
$ sudo virsh pool-refresh default
$ sudo virsh vol-delete --pool default doamin_name.qcow2
To create a new virtual machine with virsh, we can use the following command:
$ sudo virt-install
To connect to the guest console, use the command:
$ sudo virsh console domain_name
To edit a VM XML file, we can use the following command:
# To use vim text editor
$ sudo EDITOR=vim virsh edit domain_name
# To use nano text editor
$ sudo EDITOR=nano virsh edit domain_name
To suspend a guest we can use the following command:
$ sudo virsh suspend domain_name
To restore a suspended guest VM, we can use the following command:
$ sudo virsh resume domain_name
To save the current state of a VM to a file, we can use the following command:
$ sudo virsh save domain_name domain_name.save
$ ls -l domain_name.saved
To restore the saved VM from the file, we can use the following command:
$ virsh restore domain_name.save
$ sudo virsh list
Now let us see how to create a storage volume, attach it to a VM, detach it from a VM and how to delete a volume.
To create a 2GB volume named domain_name_vol2 on the default storage pool, we can use the following command:
$ sudo virsh vol-create-as default domain_name_vol2.qcow2 2G
$ sudo du -sh /var/lib/libvirt/images/domain_name_vol2.qcow2
To attach created volume above to VM domain_name, we can use the following command:
# virsh attach-disk --domain domain_name \
--source /var/lib/libvirt/images/domain_name_vol2.qcow2 \
--persistent --target vdb
To detach the above volume domain_name_vol2 from the VM domain_name, we can use the following command:
$ sudo virsh detach-disk --domain domain_name --persistent --live --target vdb
To delete volume, we can use the following commands:
$ sudo virsh vol-delete domain_name_vol2.qcow2 --pool default
$ sudo virsh pool-refresh default
$ sudo virsh vol-list default
This article will guide you on how to use to manage KVM guest virtual #machines using virsh #commands.
virsh is a command line utility for managing virsh guest domains/virtual machines and the #hypervisor.
Linux list a KVM vm guest using #virsh command.
The main command interface used to control both Solaris xVM and guest domains is the virsh command. virsh provides a generic and stable interface for controlling virtualized operating systems.
Many virsh commands act asynchronously. This means that the system prompt can return before the operation has completed.
#KVM lets you turn Linux into a hypervisor that allows a host machine to run multiple, isolated virtual environments called guests or virtual machines (VMs).
To log into VM with Virsh, simply:
1. Open a shell prompt or login using ssh.
2. Login to a host server called server1.
3. Use the virsh console command to log in to a running VM called 'centos7' type: virsh console centos7.
The virsh destroy #command initiates an immediate ungraceful shutdown and stops the specified guest virtual machine.
Using virsh destroy can corrupt guest virtual machine file systems.
Use the virsh destroy command only when the guest virtual machine is unresponsive.