Configure a KVM Host

To manage an Oracle Linux KVM host using Oracle Linux Virtualization Manager, prepare the KVM host by performing a fresh installation of Oracle Linux 8.8 (or later Oracle Linux 8 release) and enabling the required repositories, and then you add the host to a data center using the Administration Portal.

Before you begin, ensure you have satisfied the KVM Host Requirements as detailed in the Oracle Linux Virtualization Manager: Architecture and Planning Guide.

Refer to the Oracle^® Linux: KVM User's Guide for information on the supported guest operating systems.

Prepare a KVM Host

Before you can add an Oracle Linux KVM host, prepare it by performing a fresh installation of Oracle Linux 8.8 (or later Oracle Linux 8 release) and enabling the required repositories. You can download the installation ISO for Oracle Linux 8.8 (or later Oracle Linux 8 release) from the Oracle Software Delivery Cloud at https://edelivery.oracle.com.

Install Oracle Linux 8.8 (or later Oracle Linux 8 release) on the host.
- Follow the instructions in the Oracle^® Linux 8: Installing Oracle Linux.
- Select Minimal Install as the base environment for the installation.
  
  Caution:
  
  Do NOT select any other base environment than Minimal Install for the installation or your hosts will have incorrect qemu and libvirt versions, incorrect repositories configured, and no access to virtual machine consoles.
- Do not install any additional packages until after you have added the host to the Manager, because they may cause dependency issues.
(Optional) If you use a proxy server for Internet access, configure Yum with the proxy server settings. For more information, see the Oracle^® Linux: Managing Software on Oracle Linux.
Complete one of the following sets of steps:
- For ULN registered hosts or using Oracle Linux Manager
  
  Subscribe the system to the required channels and enable appstream modules.
  1. For ULN registered hosts, log in to https://linux.oracle.com with your ULN user name and password. For Oracle Linux Manager registered hosts, access your internal server URL.
  2. On the Systems tab, click the link named for the host in the list of registered machines.
  3. On the System Details page, click Manage Subscriptions.
  4. On the System Summary page, select each required channel from the list of available channels and click the right arrow to move the channel to the list of subscribed channels. Subscribe the system to the following channels:
    - ol8_x86_64_baseos_latest
    - ol8_x86_64_appstream
    - ol8_x86_64_kvm_appstream
    - ol8_x86_64_ovirt45
    - ol8_x86_64_ovirt45_extras
    - ol8_x86_64_gluster_appstream
    - ol8_x86_64_addons
    - (For VDSM) ol8_x86_64_UEKR7
  5. Click Save Subscriptions.
  6. Install the Oracle Linux Virtualization Manager Release 4.5 package, which automatically enables/disables the required repositories.
```
# dnf install oracle-ovirt-release-45-el8                    
```
- For Oracle Linux yum server configured KVM hosts
  
  Install the Oracle Linux Virtualization Manager Release 4.5 package and enable the required repositories.
  
  Note:
  
  Installing the Oracle Linux Virtualization Manager Release 4.5 package configures an Oracle Linux KVM host; it does not install the Manager.
  1. Enable the ol8_baseos_latest repository.
```
# dnf config-manager --enable ol8_baseos_latest
```
  2. Install the Oracle Linux Virtualization Manager Release 4.5 package, which automatically enables/disables the required repositories.
```
# dnf install oracle-ovirt-release-45-el8
```
  3. Use the dnf command to verify that the required repositories are enabled.
    1. Clear the dnf cache.
```
# dnf clean all                                     
```
    2. List the configured repositories and verify that the required repositories are enabled.
```
# dnf repolist                    
```
      The following repositories must be enabled:
      - ol8_baseos_latest
      - ol8_appstream
      - ol8_kvm_appstream
      - ovirt-4.5
      - ovirt-4.5-extra
      - ol8_gluster_appstream
      - (For VDSM) ol8_UEKR7
    3. If a required repository is not enabled, use the dnf config-manager to enable it.
```
# dnf config-manager --enable repository
```
If your host is running UEK R7:
1. Install the Extra kernel modules package.
```
# dnf install kernel-uek-modules-extra
```
2. Reboot the host.
(Optional) Complete the previous steps to prepare additional KVM hosts.

The Oracle Linux KVM host is now ready to be added to the Manager using the Administration Portal.

Add a KVM Host

Once you have configured an Oracle Linux KVM host, you use the Administration Portal to add the host to a data center so that it can be used to run virtual machines. You can follow the steps below to add KVM hosts installed with other supported guest operating systems.

Important:

Oracle Linux Virtualization Manager allows you to overallocate a KVM host's memory and CPU resources. As the KVM host itself also needs memory and CPU in order to run, Oracle recommends that you reserve some memory and CPU for the KVM host. To do this, go to Administration and set a memory quota and a vCPU quota.

To add an Oracle Linux KVM host:

Log in to the Administration Portal.

See Log in to the Administration Portal for details.
Go to Compute and then click Hosts.
On the Hosts pane, click New.

The New Host dialog box opens with the General tab selected on the sidebar.
From the Host Cluster drop-down list, select the data center and host cluster for the host.

The Default data center is auto-selected.

When you install Oracle Linux Virtualization Manager, a data center and cluster named Default is created. You can rename and configure this data center and cluster, or you can add new data centers and clusters, to meet your needs. See the Data Centers or Clusters tasks in the Oracle Linux Virtualization Manager: Administration Guide.
In the Name field, enter a name for the host.
In the Hostname field, enter the fully-qualified domain name or IP address of the host.
In the SSH Port field, change the standard SSH port 22 if the SSH server on the host uses a different port.
Under Authentication, select the authentication method to use.

Oracle recommends that you select SSH PublicKey authentication. If you select this option, copy the key displayed in the SSH PublicKey field to the /root/.ssh/authorized_keys file on the host.

Otherwise, enter the root user's password to use password authentication.
(Optional) Configure other settings for the host from the other tabs on the New Host sidebar.

Note:

If you do not want to set any other configuration options now, you can always make changes later by selecting a host from the Hosts pane and clicking Edit.
Click OK.

The Power Management Configuration screen is displayed.
Do one of the following:
- If you do not want to configure power management, click OK.
- Click Configure Power Management and then click OK. See Configure Power Management and Fencing for Host for more information.
The host is added to the list of hosts in the Manager. While the Manager is installing the host agent (VDSM) and other required packages on the host, the status of the host is shown as Installing. You can view the progress of the installation in the Hosts details pane. When the installation is complete, the host status changes to Up.
(Optional) Complete the previous steps to add more KVM hosts to the Manager.

Note:

After a KVM host is added to a cluster, it is also crucial to avoid any spontaneous changes to the network configuration in /etc/sysconfig/network-scripts/ or through the NetworkManager (e.g. nmcli). All changes to the network configuration should be carried out through the engine host/manager Administration Portal or REST API.

Now that you have your engine and host(s) configured, see the Oracle Linux Virtualization Manager: Administration Guide for detailed configuration and administrative tasks.