Red Hat SummitEste conteúdo não está disponível no idioma selecionado.
Chapter 4. Starting virtual machines
To start a virtual machine (VM) in RHEL 9, you can use the command line or the web console GUI.
Prerequisites
- Before a VM can be started, it must be created and, ideally, also installed with an OS. For instruction to do so, see Creating virtual machines.
4.1. Starting a virtual machine by using the command line
You can use the command line (CLI) to start a shut-down virtual machine (VM) or restore a saved VM. By using the CLI, you can start both local and remote VMs.
Prerequisites
- An inactive VM that is already defined.
- The name of the VM.
For remote VMs:
- The IP address of the host where the VM is located.
- Root access privileges to the host.
Procedure
For a local VM, use the
virsh startutility.For example, the following command starts the demo-guest1 VM.
# virsh start demo-guest1 Domain 'demo-guest1' startedFor a VM located on a remote host, use the
virsh startutility along with the QEMU+SSH connection to the host.For example, the following command starts the demo-guest1 VM on the 192.0.2.1 host.
# virsh -c qemu+ssh://root@192.0.2.1/system start demo-guest1 root@192.0.2.1's password: Domain 'demo-guest1' started
Additional resources
-
The
virsh start --helpcommand - Setting up easy access to remote virtualization hosts
- Starting virtual machines automatically when the host starts
4.2. Starting virtual machines by using the web console
If a virtual machine (VM) is in the shut off state, you can start it by using the RHEL 9 web console. You can also configure the VM to be started automatically when the host starts.
Prerequisites
- You have installed the RHEL 9 web console.
- You have enabled the cockpit service.
Your user account is allowed to log in to the web console.
For instructions, see Installing and enabling the web console.
- The web console VM plug-in is installed on your system.
- An inactive VM that is already defined.
- The name of the VM.
Procedure
In the interface, click the VM you want to start.
A new page opens with detailed information about the selected VM and controls for shutting down and deleting the VM.
Click .
The VM starts, and you can connect to its console or graphical output.
Optional: To configure the VM to start automatically when the host starts, toggle the
Autostartcheckbox in the Overview section.If you use network interfaces that are not managed by libvirt, you must also make additional changes to the systemd configuration. Otherwise, the affected VMs might fail to start, see starting virtual machines automatically when the host starts.
4.3. Starting virtual machines automatically when the host starts
When a host with a running virtual machine (VM) restarts, the VM is shut down, and must be started again manually by default. To ensure a VM is active whenever its host is running, you can configure the VM to be started automatically.
Prerequisites
Procedure
Use the
virsh autostartutility to configure the VM to start automatically when the host starts.For example, the following command configures the demo-guest1 VM to start automatically.
# virsh autostart demo-guest1 Domain 'demo-guest1' marked as autostarted
If you use network interfaces that are not managed by
libvirt, you must also make additional changes to the systemd configuration. Otherwise, the affected VMs might fail to start.NoteThese interfaces include for example:
-
Bridge devices created by
NetworkManager -
Networks configured to use
<forward mode='bridge'/>
In the systemd configuration directory tree, create a
virtqemud.service.ddirectory if it does not exist yet.# mkdir -p /etc/systemd/system/virtqemud.service.d/Create a
10-network-online.confsystemd unit override file in the previously created directory. The content of this file overrides the default systemd configuration for thevirtqemudservice.# touch /etc/systemd/system/virtqemud.service.d/10-network-online.confAdd the following lines to the
10-network-online.conffile. This configuration change ensures systemd starts thevirtqemudservice only after the network on the host is ready.[Unit] After=network-online.target
-
Bridge devices created by
Verification
View the VM configuration, and check that the autostart option is enabled.
For example, the following command displays basic information about the demo-guest1 VM, including the autostart option.
# virsh dominfo demo-guest1 Id: 2 Name: demo-guest1 UUID: e46bc81c-74e2-406e-bd7a-67042bae80d1 OS Type: hvm State: running CPU(s): 2 CPU time: 385.9s Max memory: 4194304 KiB Used memory: 4194304 KiB Persistent: yes Autostart: enable Managed save: no Security model: selinux Security DOI: 0 Security label: system_u:system_r:svirt_t:s0:c873,c919 (enforcing)If you use network interfaces that are not managed by libvirt, check if the content of the
10-network-online.conffile matches the following output.$ cat /etc/systemd/system/virtqemud.service.d/10-network-online.conf [Unit] After=network-online.target
Additional resources
-
The
virsh autostart --helpcommand - Starting virtual machines by using the web console.
